Advanced Direct Exchange Geothermal Heating/Cooling System Design

ABSTRACT

A direct expansion/direct exchange (“DX”) geothermal heating/cooling system having a plurality of pin restrictors positioned in housing units at ground accessible locations. The pin restrictors are preferably located near the compressor unit and on the field side of the distributor. Refrigerant is substantially equally distributed by a distributor to substantially equally sized line sets in the DX system with multiple wells. The distributors are place in either horizontal or vertical inclinations with the pin restrictors situated on the field side of the distributor in each individual liquid refrigerant transport line. A cut-off ball valve is located within the liquid refrigerant transport line on each side of the respective pin restrictor housing units. A filter/dryer is place within the same liquid refrigerant transport line segment as the pin restrictor(s) with a refrigerant flow shut-off valve being situated on each side of the liquid line segment containing the filter/dryer and the distributor.

This is a non-provisional application claiming priority based uponco-pending U.S. Patent Application Ser. No. 60/806,739 filed Jul. 7,2006 entitled “Advanced Direct Exchange Geothermal Heating/CoolingSystem Design.”

I, B. Ryland Wiggs, of Franklin, Tenn., have invented a new and useful“Advanced Direct Exchange Geothermal Heating/Cooling System Design”.

A portion of the disclosure of this patent document contains materialthat is subject to copyright. The copyright owner has no objection tothe authorized facsimile reproduction by anyone of the patent documentor the patent disclosure, as it appears in the Patent and TrademarkOffice patent file or records, but otherwise reserves all copyrightrights whatsoever.

All patents and publications discussed herein are hereby incorporated byreference in their entirety.

BACKGROUND OF THE INVENTION

The present invention relates to a geothermal direct exchange (“DX”)heating/cooling system, which is also commonly referred to as a “directexpansion” heating/cooling system, comprising various designimprovements.

Geothermal ground source/water source heat exchange systems typicallyutilize fluid-filled closed loops of tubing buried in the ground, orsubmerged in a body of water, so as to either absorb heat from, or toreject heat into, the naturally occurring geothermal mass and/or watersurrounding the buried or submerged fluid transport tubing. The tubingloop is extended to the surface and is then used to circulate one of thenaturally warmed and naturally cooled fluid to an interior air heatexchange means.

Common and older design geothermal water-source heating/cooling systemstypically circulate, via a water pump, a fluid comprised of water, orwater with anti-freeze, in plastic (typically polyethylene) undergroundgeothermal tubing so as to transfer geothermal heat to or from theground in a first heat exchange step. Via a second heat exchange step, arefrigerant heat pump system is utilized to transfer heat to or from thewater. Finally, via a third heat exchange step, an interior air handler(comprised of finned tubing and a fan) is utilized to transfer heat toor from the refrigerant to heat or cool interior air space.

Newer design geothermal DX heat exchange systems, where the refrigerantfluid transport lines are placed directly in the sub-surface groundand/or water, typically circulate a refrigerant fluid, such as R-22 orthe like, in sub-surface refrigerant lines, typically comprised ofcopper tubing, to transfer geothermal heat to or from the sub-surfaceelements via a first heat exchange step. DX systems only require asecond heat exchange step to transfer heat to or from the interior airspace, typically by means of an interior air handler. Consequently, DXsystems are generally more efficient than water-source systems becauseless heat exchange steps are required and because no water pump energyexpenditure is necessary. Further, since copper is a better heatconductor than most plastics, and since the refrigerant fluidcirculating within the copper tubing of a DX system generally has agreater temperature differential with the surrounding ground than thewater circulating within the plastic tubing of a water-source system,generally, less excavation and drilling is required, and installationcosts are lower, with a DX system than with a water-source system.

While most in-ground/in-water DX heat exchange designs are feasible,various improvements have been developed intended to enhance overallsystem operational efficiencies. Several such design improvements,particularly in direct expansion/direct exchange geothermal heat pumpsystems, are taught in U.S. Pat. No. 5,623,986 to Wiggs; in U.S. Pat.No. 5,816,314 to Wiggs, et al.; in U.S. Pat. No. 5,946,928 to Wiggs; andin U.S. Pat. No. 6,615,601 B1 to Wiggs, the disclosures of which areincorporated herein by reference. Such disclosures encompass bothhorizontally and vertically oriented sub-surface heat geothermal heatexchange means, utilizing historically conventional refrigerants, suchas R-22, as well as utilizing a newer design of refrigerant identifiedas R-410A. R-410A is an HFC azeotropic mixture of HFC-32 and HFC-125.

DX heating/cooling systems have several primary objectives. The first isto provide the greatest possible operational efficiencies. This directlytranslates into providing the lowest possible heating/coolingoperational costs, as well as other advantages, such as, for example,materially assisting in reducing peaking concerns for utility companies.The second is to operate in an environmentally safe manner via theutilization of environmentally safe components and fluids.

Historically, DX heating/cooling systems, even though more efficientthan other conventional heating/cooling systems, have experiencedpractical limitations created by the relatively large surface land areasnecessary to accommodate the sub-surface heat exchange tubing. Forexample, with R-22 systems, a typical land area of 500 square feet perton of system design capacity was required in first generation designsto accommodate a shallow (within 10 feet of the surface) matrix ofmultiple, distributed, copper heat exchange tubes, or about one to two50 foot to 100 foot (maximum) depth wells/boreholes per ton of systemdesign capacity, spaced at least about 20 feet apart, were required.Such requisite surface areas effectively precluded system applicationsin many commercial and/or high density residential applications. Animprovement over such predecessor designs was taught by Wiggs via theutilization of an R-410A refrigerant that operated at about a 40% higherpressure than R-22 systems, and that were able to efficiently operate atDWDX system depths, of about 300 to 350 feet per well/borehole.

While a number of former DX system designs work, as a primary objectiveis to increase the efficiency and reliability of DX system designs,particularly in light of rapidly accelerating energy costs, extensivetesting has demonstrated a number of design improvements that willenhance the efficiency and reliability of older DX system designs.

It is an object of the subject inventions to improve upon earlier andformer DX system technologies, so as to provide ultra-efficient,environmentally safe, DX system designs. The present inventions providea solution to these preferable objectives, as hereinafter more fullydescribed.

SUMMARY OF THE INVENTION

The subject inventions primarily relate to DX system advantages wheninstalled with DWDX system vertically oriented sub-surface geothermalheat exchange means, although various advantages are also present innear-surface (100 feet deep or less) DX system applications,particularly such as involving a trench system design, a pit systemdesign, or any combination of the above. Thus, it is an object of thepresent inventions to further enhance and improve the efficiency andpractical applicability of predecessor direct expansion/direct exchange(“DX”) geothermal heating/cooling systems. This is accomplished by meansof providing the following:

1. Providing pin restrictors, in housing units, at an accessiblelocation, typically above-ground, for a DX system operating in theheating mode, where the pin restrictors are preferably located near thecompressor unit, but on the field side of any distributor. Typicalpredecessor DX system designs utilized self-adjusting expansion valvesin the heating mode, or utilized manually adjusted heating valves. Theproblem with self-adjusting heating valves in a DX system in the heatingmode is that the refrigerant has to travel so far in the sub-surfaceenvironment, the automatic valve is constantly “hunting” for an optimumsetting, resulting in rather continuous and inefficient swings in setpoints. The problem with a manually adjusted valve is that a preciseoptimum setting is a matter of luck, rather than design. Earlier pinrestrictor designs by Wiggs taught the placement of the heating mode pinrestrictors at or near the bottom of a deep well DX system design, or atthe distal end of a mostly horizontal sub-surface refrigerant transporttubing design. While this design was a major improvement overpredecessor technology, providing uniform refrigerant flow throughsystems with multiple combined wells/line sets, the ability to serviceor change the pin restrictor was cumbersome. Therefore, the placement ofthe pins in an above-ground location, in a manner so as to still insureuniform refrigerant flow through systems with multiple combinedwells/line sets would be preferable. This is accomplished by means ofequally distributing refrigerant flow through a distributor to equallysized line sets in a system with multiple wells, all while placing thedistributors in at least one of an exactly horizontal and a verticalinclination, with the pin restrictors situated on the field side of thedistributor in each individual liquid refrigerant transport line goingto the subsurface geothermal heat transfer field below ground/waterlevel. An individual liquid refrigerant transport line must bedistributed to each pin restrictor. Further, it is advantageous toinsure the pin restrictors are easily serviced by means of a cut-offball valve located within the liquid refrigerant transport line on eachside of respective pin restrictor housing units. Placing pin restrictorson each individual distributed liquid refrigerant transport line helpsto insure an equal refrigerant flow rate and pressure into eachrespective geothermal heat exchange loop, and also provides a means tocheck for any restrictions in individual distributed heat exchangeloops.

Further, the use of a filter/dryer for refrigerant is a useful andcommon piece of equipment used in DX systems, as is well understood bythose skilled in the art. However, historically in the DX field,filter/dryers have been placed within the compressor box itself. Thus,when the filter/dryer needs to be changed, the historical and commonpractice in the DX HVAC field has been to open the compressor box,re-claim all refrigerant the within the box, change the filter/dryer,and then replace the refrigerant that had been reclaimed. Typically,many compressor boxes in the DX field even have no isolation valves soas to limit refrigerant reclaiming to the refrigerant within the box.Thus, a design improvement, so as to materially facilitate servicing andreduce servicing time/expense, would be to place the filter/dryer withinthe same liquid refrigerant transport line segment as the pinrestrictor(s), with a refrigerant flow shut-off valve being situated oneach side of the liquid line segment containing the filter/dryer and thedistributor (if there are more than one sub-surface liquid refrigeranttransport lines).

Since such a liquid line segment will be relatively heavy. Thus, so asnot to incur a bent or crimped liquid refrigerant transport line viagravity over a period of time, it would be preferable for the field sidecut-off valves to be situated on at least one of the ground and a solidsupport so as to carry the weight of the subject liquid line segment.

Restrictions in at least one of a distributed geothermal heat exchangeloop will be evidenced by a decreased refrigerant flow rate, by a highertemperature in the cooling mode and/or by a lower temperature in theheating mode. The cut-off valves on the other geothermal heat exchangeloop(s) can be slightly engaged, a little at a time, until the looptemperatures of an operational system all evenly match. When thetemperatures all match, the amount of restriction to the good geothermalheat exchange loop, via the degree of cut-off valve engagement, can bemeasured to determine the amount of restriction in the bad, restricted,heat exchange loop. If all multiple loops combined, with equalrestrictions in each, provide the minimum necessary refrigerant flowrate for the particular DX system, the faulty restricted loop will nothave to be replaced.

2. The sizing of the heating mode pin restrictors for a DX systemoperating in the heating mode, with R-410A refrigerant, must be withinthe following size parameters, plus no more than 5%, and less no morethan 17% of the area of each below identified pin diameter size ininches. If the pin size is increased by more than 5%, the sensibleinterior heat produced is lowered and the operational efficiency levelsdecrease. If the pin size is decreased by more than 17%, when oneswitches from the cooling mode to the heating mode at the end of acooling season, the head pressure of the refrigerant may be excessivelyhigh, so as to shut the system off via its internal high pressurecut-off switch.

((or formula) (Calculation is 15% to 30% less than conventional R-22chart sizes, with 15% being preferable to permit cooling to heatingswitch-over without too high of a head pressure.) (Plus, one must addadditional refrigerant to offset the increased superheat caused by thesmaller pin size, or premature compressor failure will result . . . thisis taken into account in charging formula.)) *For A Single Line SetTrench System or DWDX System (One Pin) - Heating Mode Compressor SizePin Diameter Size In Inches 13,400 0.033 16,000 0.036 18,000 0.03819,000 0.039 20,000 0.040 20,100 0.040 21,000 0.042 22,000 0.043 23,0000.044 24,000 0.045 25,000 0.046 26,000 0.047 26,800 0.048 27,000 0.04828,000 0.049 29,000 0.050 30,000 0.051 31,000 0.051 32,000 0.052 33,0000.053 34,000 0.053 35,000 0.054 36,000 0.054 37,000 0.055 38,000 0.05639,000 0.056 40,000 0.057 41,000 0.057 42,000 0.058 43,000 0.058 44,0000.059 45,000 0.059 46,000 0.059 47,000 0.060 48,000 0.060 49,000 0.06050,000 0.061 51,000 0.061 52,000 0.062 53,000 0.062 54,000 0.063 55,0000.063 56,000 0.064 57,000 0.064 58,000 0.065 59,000 0.065 60,000 0.065

*For A Double Line Set Trench System or DWDX System (Two Pins . . . OneRespectively Sized Pin In Each of the Two Pin Housing Sections of theLiquid Line Assembly Segment) - Heating Mode Compressor Size PinDiameter Size In Inches 26,000 0.033 27,000 0.034 28,000 0.035 29,0000.035 30,000 0.036 31,000 0.036 32,000 0.037 33,000 0.037 34,000 0.03834,170 0.038 35,000 0.038 36,000 0.038 37,000 0.039 38,000 0.040 39,0000.040 40,000 0.040 41,000 0.041 42,000 0.041 43,000 0.041 44,000 0.04245,000 0.042 46,000 0.042 47,000 0.042 48,000 0.042 49,000 0.043 50,0000.043 51,000 0.043 52,000 0.044 53,000 0.044 54,000 0.044 55,000 0.04556,000 0.045 57,000 0.045 58,000 0.046 59,000 0.046 60,000 0.046

*For A Triple Line Set Trench System or DWDX System (Three Pins . . .One Respectively Sized Pin In Each of the Three Pin Housing Sections ofthe Liquid Line Assembly Segment) - Heating Mode Compressor Size PinDiameter Size In Inches 54,000 0.036 55,000 0.036 56,000 0.037 57,0000.037 58,000 0.037 59,000 0.038 60,000 0.038 83,000 0.044

*For A Quadruple Line Set Trench System or DWDX System (Four Pins . . .One Respectively Sized Pin In Each of the Four Pin Housing Sections ofthe Liquid Line Assembly Segment) - Heating Mode Compressor Size PinSize 83,000 0.038

In the alternative, the following formula may be used to determine thecorrect heating mode pin size:

For a 13,400 BTU through a 44,000 BTU compressor size (not air handlersize and not system design size, but the actual size of the compressorin the compressor unit/box), multiply the compressor size in thousandthsby 0.000065. Match the resulting number, which will be the area of theorifice, to the closest pin size diameter. For example, if the systemhas a 21,000 BTU compressor, multiple 21 by 0.000065, which equals a0.001365 area, which is nearest to a 0.042 pin restrictor size diameter.

For a 45,000 BTU through a 60,000 BTU compressor size (not air handlersize and not system design size, but the actual size of the compressorin the compressor unit/box), multiply the compressor size in thousandthsby 0.000058. Match the resulting number, which will be the area of theorifice, to the closest pin size diameter. For example, if the systemhas a 54,000 BTU compressor, multiple 54 by 0.000058, which equals a0.003132 area, which is nearest to a 0.063 pin restrictor size diameter.

Regarding the above formula, when one wishes to use two, three, or morepin restrictors for one system, in a situation where the heat exchangetubing is distributed into two or more geothermal heat exchangesub-surface fields, the final calculated area needs to be divided by 2,3, etc., and then matched to the nearest pin size used.

3. Although in a typically cooling to heating season period, the ground,which has been absorbing rejected heat all summer, will typically coolenough to permit instant DX system heating mode operation with only aproperly sized heating mode pin restrictor, if the seasonal change isextremely abrupt and fast, a pressure regulated heating mode refrigerantby-pass vale within a heating mode by-pass line around the heating modepin restrictor may be necessary so as to permit instant system heatingmode operation without the system tripping off via its safety highpressure cut off switch. To accomplish this optional heating modeprotective means, one should preferably add a heating mode by-passpressure regulated valve, also referred to as an automatic expansionvalve (“AXV”), so as to assist transition from the cooling mode to theheating mode so that the valve opens to an interior diameter of at leastthe size of the actual BTU size, in thousandths, of the compressor inthe compressor unit/box multiplied by 0.00008, with no less thanmultiplied by 0.00006, and with preferably no more than multiplied by0.00016, to be opened when the refrigerant head pressure is 375 psi(plus or minus 5 psi) or greater, and to be closed when the refrigeranthead pressure is below 375 psi (plus or minus 5 psi). Match theresulting number, which will be the area of the orifice, to the closestpin size diameter if to be measured in pin restrictor sizing. The higherthe refrigerant pressure, the greater the opening in the valve. Thevalve should begin to open at an 0.00008, and should be no larger than0.00016. When the DX system refrigerant head pressure in the heatingmode is less than 375 psi, the valve will be fully closed, therebyforcing the refrigerant flow through the properly designed pinrestrictor orifice opening only.

4. The cooling mode TXV by-pass pin restrictor size must be within thefollowing size parameters: COMPRESSOR BTU SIZE (NOT TS MODEL SIZE) PINSIZE IN INCHES 16,000 .044 18,000 .048 21,000 .050 24,000 .054 25,000.055 26,000 .056 29,000 .059 32,000 .062 33,000 .062 34,000 .062 35,000.063 36,000 .064 38,000 .065 42,000 .069 44,000 .070 48,000 .073 50,000.075 51,000 .076 54,000 .078 55,000 .079 56,000 .080 57,000 .081 60,000.083 83,000 .098

In the alternative, the following formula may be used to determine thecorrect TXV by-pass pin size:

For a 21,000 BTU through a 32,000 BTU compressor size (not air handlersize and not system design size, but the actual size of the compressorin the compressor unit/box), multiply the compressor size in thousandthsby 0.000095. Match the resulting number, which will be the area of theorifice, to the closest pin size diameter. For example, if the systemhas a 21,000 BTU compressor, multiple 21 by 0.000095, which equals a0.001995 area, which is nearest to a 0.050 pin restrictor size diameter.

For a 33,000 BTU compressor size (not air handler size and not systemdesign size, but the actual size of the compressor in the compressorunit/box), multiply the compressor size in thousandths by 0.000091.Match the resulting number, which will be the area of the orifice, tothe closest pin size diameter. For example, if the system has a 33,000BTU compressor, multiple 33 by 0.000091, which equals a 0.0030 area,which is nearest to a 0.062 pin restrictor size diameter.

For a 34,000 BTU through a 55,000 BTU compressor size (not air handlersize and not system design size, but the actual size of the compressorin the compressor unit/box), multiply the compressor size in thousandthsby 0.000088. Match the resulting number, which will be the area of theorifice, to the closest pin size diameter. For example, if the systemhas a 48,000 BTU compressor, multiple 48 by 0.000088, which equals a0.004224 area, which is nearest to a 0.073 pin restrictor size diameter.

For a 56,000 BTU through a 83,000 BTU compressor size (not air handlersize and not system design size, but the actual size of the compressorin the compressor unit/box), multiply the compressor size in thousandthsby 0.00009. Match the resulting number, which will be the area of theorifice, to the closest pin size diameter. For example, if the systemhas a 60,000 BTU compressor, multiple 60 by 0.00009, which equals a0.0054 area, which is nearest to a 0.083 pin restrictor size diameter.

Regarding the above formulas, when one wishes to use two, three, or morepin restrictors for one system, in a situation where the heat exchangetubing is distributed into two or more air handlers, for example, thefinal calculated area needs to be divided by 2, 3, etc., and thenmatched to the nearest pin size used.

5. Add a cooling mode TXV by-pass pressure regulated valve, alsoreferred to as an automatic expansion valve (“AXV”), so as to assisttransition from the heating mode to the cooling mode in a DX system.

Add a cooling mode by-pass pressure regulated valve, also referred to asan automatic expansion valve (“AXV”), so as to assist transition fromthe heating mode to the cooling mode so that the valve opens to aninterior diameter of at least the size of the actual BTU size, inthousandths, of the compressor in the compressor unit/box multiplied by0.00009, with no less than multiplied by 0.00009, and with preferably nomore than multiplied by 0.00018, to be opened when the refrigerantsuction pressure is 85 psi (plus or minus 5 psi) or less, and to beclosed when the refrigerant suction pressure is above 85 psi (plus orminus 5 psi). Match the resulting number, which will be the area of theorifice, to the closest pin size diameter if to be measured in pinrestrictor sizing. The lower the refrigerant pressure, the greater theopening in the valve.

Alternately, although not as precise as individually tailored by-passvalves for each respective compressor size, a one size fits all valveopening to the actual BTU size, in thousandths, of a five ton compressorin the compressor unit/box multiplied by 0.00009, with no less thanmultiplied by 0.00009, and with preferably no more than multiplied by0.00018, to be opened when the refrigerant suction pressure is 85 psi(plus or minus 5 psi) or less, and to be closed when the refrigerantsuction pressure is above 85 psi (plus or minus 5 psi), may be used forsystems with 1 through 5 ton compressor units.

The AXV should be an external equalized valve, with a capillary tubeextended from the valve to the low pressure vapor line exiting the airhandler. The valve should preferably be an adjustable type valve thatcan be set to shut off at any pressure between 40 psi and 100 psi., withan 85 psi shut off point being preferable for a DX system application.

6. For maximum cooling capacity and humidity removal, the receiver sizemust be sized at 1 pound for every 40 feet of ⅜ inch O.D. liquid linedepth within a DWDX system design, or the equivalent thereof when otherline set sizes are utilized, exclusive of the trenched line(s) to/fromthe well(s) and the compressor unit.

For maximum cooling operational efficiencies and minimum vertical wellrefrigerant pressure drop, the receiver size must be sized at 1 poundfor every 50 feet of ⅜ inch O.D. liquid line depth within a DWDX systemdesign, or the equivalent thereof when other line set sizes areutilized, exclusive of the trenched line(s) to/from the well(s) and thecompressor unit, and exclusive of any other DX system refrigerantcontainment components.

7. Differing air handler manufacturers utilize differing finned tubinglengths per ton of size design capacity. However, most air handlermanufacturers utilize finned tubing with 12 to 14 fins per inch length.Since differing manufacturers utilize differing lengths of tubing perton of design capacity, it is inefficient to prescribe a certain tonnageair handler to be used with a particular DX system BTU compressor size.Further, to optimize DX system efficiencies, testing has shown it isimpractical to match a 3 ton compressor with a 3 ton air handler, asmost all predecessor conventional system designs call for. Testing hasshown that in order to optimize the efficiency of a DX system design,the air handler must be sized to 120% of the maximum system design loadand must have 60 feet per ton, plus or minus 5 feet, of finned 3/8 inchO.D. interior heat exchange tubing. 55 to 60 feet is preferable inheating mode. 60 to 65 feet is preferable in cooling mode.

8. The DX system charging formula, using R-410A refrigerant (all knownpredecessor DX systems sold operate on an R-22, or similar, refrigerantwith significantly lower operating pressures than R-410A) for a DWDXsystem, with a preferred sub-surface ⅜ inch O.D. liquid refrigerantgrade transport line in the well/borehole, with a 0.032 inch wallthickness, and a sub-surface ¾ inch O.D., or larger, vapor refrigerantgrade geothermal heat exchange transport line in the well/borehole, iscalculated by adding the sum of the following:

A. Total depth of the ⅜ inch O.D. liquid line in well times 0.0375pounds

B. 50% of total length of finned ⅜ inch O.D. tubing in air handlermultiplied by 0.0375 pounds.

C. Compressor unit/box content of liquid refrigerant. For an ETA system,for a 1.5 to a 4 ton system, add 1.5 pounds. For a 4.1 to a 5 tonsystem, add 2 pounds.

D. Add the amount of liquid refrigerant contained in the system'sfilter/dryer (for example, a Parker Bi-Directional R-410A Heat PumpFilter/Dryer Model BF164-XF holds about 0.761875 pounds), exclusive ofthe filter/dryer in the compressor box, which has already been takeninto account in the compressor unit/box content.

E. Add the amount of liquid refrigerant in all liquid line ball cut-offvalves (typically about 0.05 pounds), exclusive of the ball cut-offvalves in the compressor box, which have already been taken into accountin the compressor unit/box content.

F. Measure the total liquid transport line length between the top of thewell/borehole and the compressor unit/box and multiply by the fullliquid weight content of the line in pounds. For example, multiply by0.0375 pounds if it is a ⅜ inch O.D. line, but multiply by 0.06875 if itis a ½ inch O.D line.

G. Measure the total liquid transport line length between the airhandler and the compressor unit/box and multiply by the full liquidweight content of the line in pounds. For example, multiply by 0.0375pounds if it is a ⅜ inch O.D. line, but multiply by 0.06875 if it is a ½inch O.D line.

H. For a cooling mode charge, add an additional 1 pound of refrigerantfor every 40 feet of ⅜ inch O.D. refrigerant grade liquid line in thewell for maximum system operational capacity and humidity removal. Ifhumidity removal is not a concern, add an additional 1 pound ofrefrigerant for every 50 feet of ⅜ inch O.D. refrigerant grade liquidline in the well for maximum efficiency.

I. If the system is designed to operate in a reverse-cycle mode (heatingand cooling), the system must have a liquid line receiver that holds thepreferred charge differential between the heating mode and the coolingmode. Additionally, the receiver will have some constant amount ofliquid content in its bottom, regardless of the system operational mode,which constant amount of refrigerant, in pounds, must be added. Forexample, a typically well designed receiver usually always holds 0.75pounds, regardless of whether operating in the heating or the coolingmode.

Prior DX system designs with receivers either failed to specify areceiver with only one refrigerant entrance and exit and/or failed tospecify the amount of refrigerant the receiver was to hold and/orreferenced a receiver percentage content equal to some uniformpercentage (such as 40% for example) of the total system charge,typically all without defining how to determine the exact system charge.Consequently, prior DX receiver designs have been generally useless.Testing has shown that the receiver content must be as hereinabovedescribed, with only one refrigerant entrance and exit, for areverse-cycle DX system to operate at one of its optimum capacity andefficiency. No known person has heretofore discovered or taught thereceiver capacity in a DX system is dependent upon well/borehole depthwith specified and certain liquid refrigerant transport line sizes.

J. If the system is designed to operate in the heating mode with aheating mode pin expansion device installed, the weight, in pounds, ofthe liquid content of the pin restrictor housing design must be added tothe total.

The total of the appropriate above sums will equal the correct systemcharge.

To determine the optimum charge in DX systems utilizing other than ⅜inch O.D. liquid refrigerant transport lines and ¾ inch O.D. vaporrefrigerant transport lines, the charge should preferably be determinedby the above formula, except the equivalent refrigerant content of theactual interior volume of the liquid refrigerant transport line usedmust be matched to the interior volume of a ⅜ O.D. liquid refrigeranttransport line as per the above formula. For example, if multiple liquidrefrigerant transport lines of a smaller interior diameter were utilizedthan that of a ⅜ inch O.D. refrigerant grade copper tube, then thecontent of all multiple smaller lines must match that of the content ofa system designed with at least one of one and multiple ⅜ inch O.D.refrigerant grade copper tube(s). As another example, if a larger liquidrefrigerant transport line was used than that of a ⅜ inch O.D.refrigerant grade copper tube, then the interior content of the largertube must match that of the content of a system designed with at leastone of one and multiple ⅜ inch O.D. refrigerant grade copper tube(s).

9. Place a rubber mat over the top of all DX system geothermal heatexchange wells in lightening prone areas. Additionally, in areas proneto lightening strikes, all copper tubing within trenches between wellsand compressor units should preferably be insulated with plastic orrubber material that is not electrically conductive, such as expandedfoam polyethylene and/or neoprene. This will assist in mitigatinglightening strikes in lightening prone areas, such as Florida.

Copper tubing well installation spools, with pre-assembled line sets forDX system field loop installations, should preferably have at least a 24inch wide holding tube diameter, with both insulated and un-insulatedrefrigerant transport lines on the same holding spool, with spiraledfiber tape to keep the lines together. The holding spool shouldpreferably have sides extending past the outer layer of the refrigeranttransport lines, but with a four foot, or less, diameter so as tofacilitate shipping on a four foot wide pallet. Prior to assembly, theline set, with a cementitious grout-filled (preferably Grout 111)“Torpedo” unit surrounding the liquid refrigerant transport line U bendand the liquid refrigerant transport line coupling to the vaporrefrigerant transport line at the bottom, should be evacuated of airwith a vacuum pump (typically an electrically operated pump) to at leasta 250 micron vacuum, and then charged with a dry nitrogen holding chargeof 50 pounds, or the like, for shipment and installation. Pulling thevacuum and charging with dry nitrogen is accomplished via sealing one ofthe liquid and vapor refrigerant transport lines shut and installing aschraeder valve on the other for gauge set attachment and hook up to thevacuum pump and then to the pressurized bottle of dry nitrogen, as iswell understood by those skilled in the art.

The 250 micron vacuum will insure there are no leaks, and the 50 poundholding charge will insure no leaks have occurred during either shipmentor installation. Both pulling the vacuum and inserting the holdingcharge of dry nitrogen are effected by means of capping one of the endsof the liquid refrigerant transport line and vapor refrigerant transportlines, and placing a schraeder valve (a schraeder valve is wellunderstood by those skilled in the art) in the other for refrigerationgauge set attachment (refrigeration gauges are well understood by thoseskilled in the art). This procedure comprises a significant time savingand efficiency improvement over the historical and traditional method ofinstalling sub-surface heat exchange tubing in a DX system, where thetubing is installed, sealed, and pressure tested prior to pulling avacuum and charging, which is more time consuming and is not astrustworthy as initially pulling a vacuum. Pulling a vacuum cannot bedone to 250 microns in a DX system if there is a leak, whereas apressure test could take hours or days to reveal a very slight leak. ATorpedo unit is comprised of a tube with a rounded nose, which tubecontains refrigerant transport tubing, the lower liquid line U bend, anda cementitious grout fill material, preferably comprised of Grout 111,which Grout 111 is shrink and crack resistant, with a very high 1.4BTUs/Ft.Hr. Degrees F heat transfer rate. The rounded nose on theTorpedo unit prevents hang-ups on rugged well/borehole sides and/orledges as the copper refrigerant transport tubing line set is loweredinto the well/borehole.

The pre-assembled line set, comprised of an insulated smaller diameterliquid refrigerant transport line and an un-insulated larger diametervapor refrigerant transport line, should preferably be surrounded by aspiraled fiber tape, or the like, so as to keep the refrigeranttransport lines together as they are lowered into the well/borehole. Thetape 70 must be spiraled at least once every eight to twelve inches tobe effective.

11. A near-surface, but sub-surface, DX trench geothermal heat exchangesystem should preferably be comprised of equal lengths of a smallerdiameter un-insulated refrigerant transport tubing and of a largerdiameter un-insulated refrigerant transport tubing, and shouldpreferably be installed with at least 100 feet of refrigerant transporttubing per ton of the maximum heating/cooling BTU load design, as perACCA Manuel J or the like, where 12,000 BTUs equal one ton ofheating/cooling capacity. However, 120 feet per ton is a preferredlength to assist in insuring optimum system operational efficiencies.

In such a DX trench system, one liquid refrigerant transport line wouldbe coupled to one vapor refrigerant transport line at the distal end ofthe sub-surface heat exchange loop, with the liquid line making at leasta 6 inch vertically and downwardly oriented U bend prior to coupling tothe vapor line at the at least 6 inch higher elevation. The U bendshould be at the lowest point of the entire heat exchange loop, and thevapor line must be one of at least horizontally oriented and downwardlysloped (downwardly sloped being preferred) to the U bend. Preferably,such heat exchange loops would not exceed 360 feet in length per loop.

In such a DX trench system, the liquid refrigerant transport line wouldpreferably be comprised of one 120 foot long ⅜ inch O.D. refrigerantgrade copper tube, or the like, per ton of system design capacity, witha maximum 360 foot distance per liquid line segment in each respectiveloop.

In such a DX trench system, the vapor refrigerant transport line wouldpreferably be comprised of one 120 foot long ¾ inch O.D. refrigerantgrade copper tube, or the like, per ton of system design capacity, witha maximum 360 foot distance per vapor line segment in each respectiveloop.

In such a DX trench system, neither the vapor refrigerant transport lineused for subsurface heat exchange, nor the liquid refrigerant transportline used for subsurface heat exchange, would be insulated, and therespective vapor line and liquid line, except for being coupled togetherat the distal end of the loop, would be separated by at least 20 feet,with a 30 foot separation being preferable where land area permits. Whenthe vapor line and liquid line near one another for connection to the DXsystem compressor unit, each line should preferably be fully insulated,with a closed cell insulation (such as expanded polyethylene and/orneoprene, or the like) when they are at least within 20 feet of oneanother.

In such a near-surface trench system application, when the designcapacity calls for more than one 360 foot long loop, multiplesub-surface geothermal heat exchange loops, comprised of larger diametervapor lines coupled at their respective distal ends to respectivesmaller diameter liquid lines would preferably be joined together bymeans of a vapor line distributor and a liquid line distributor forrefrigerant transportation to the compressor unit. Here, as in a singleloop application, insulation would preferably surround all sub-surfacetubing within twenty feet of one another.

12. A DX system may be utilized where the sub-surface heat exchangetubing is installed under water. When in moving water, such as at leastone of a stream, a creek, a river, and a tidal area, and the like, a DXsystem with refrigerant transport heat exchange tubing in the movingwater needs only forty feet per ton to operate at design system tonnagecapacity (as per ACCA Manuel J or the like) with sixty feet per tonbeing preferred with a design safety margin. The heat exchange tubing,should be exposed to the water via at least one of an extended line, alooped, coiled, and largely spread apart line, a looped, coiled, andmodestly spread apart line, a series of U bends, and the like, alwayswith the heat exchange line at a downwardly sloped elevation to aconnecting liquid line, by means of a coupling, at the bottom/distalend. The refrigerant transport lines/tubing would typically beinsulated, after exiting the water, on the way to the compressor unit.

The heat exchange tubing should preferably be comprised of ¾ inch O.D.refrigerant grade copper tubing, or the like, for use in conjunctionwith up to a 30,000 BTU compressor. The heat exchange tubing shouldpreferably be comprised of ⅞ inch O.D. refrigerant grade copper tubing,or the like, for use in conjunction with a 31,000 BTU compressor up toan 83,000 BTU compressor. When smaller heat exchange tubing is used, theinterior diameter of the smaller lines should preferably approximatelyequal the interior diameter of the respective ¾ inch O.D. and ⅞ inchO.D. lines as described in this paragraph with the varying compressorsizes.

The connecting liquid line, which will travel from the distal and lowestend of the larger heat exchange tubing back to the system's compressorunit, should be comprised of ⅜ inch O.D. refrigerant grade coppertubing, or the like, for use in conjunction with up to a 30,000 BTUcompressor. The connecting liquid line, which will travel from thedistal and lowest end of the larger heat exchange tubing back to thesystem's compressor unit, should be comprised of ½ inch O.D. refrigerantgrade copper tubing, or the like, for use in conjunction with a 31,000BTU compressor up to an 83,000 BTU compressor. When smaller liquid linerefrigerant transport tubing is used, the interior diameter of thesmaller lines should preferably approximately equal the interiordiameter of the respective ⅜ inch O.D. and ½ inch O.D. lines asdescribed in this paragraph with the varying compressor sizes.

When in salt water and/or in water that is at least one of corrosive andabrasive to copper or other refrigerant transport tubing, therefrigerant transport tubing must be situated within a protectiveencasement, such as at least one of Grout 111, titanium, polyethylene,and a non-corrosive fluid filled pipe, and the like.

Alternately, the heat exchange tubing could be installed with finnedtubing within a containment box made of a resistant material, such as atleast one of titanium, Grout 111, polyethylene, and the like, to preventmicro-organism damage. Micro-organisms in seawater eat stainless steel.Preferably, such a containment box would be filled with a non-corrosivefluid, such as pure water or the like, and would have an expanded topand bottom to facilitate the collection and transfer of heat to thesurrounding water (the warmest water would naturally rise to the top ofthe containment box and the coolest water would naturally fall to thebottom of the containment box in both the cooling mode and in theheating mode, all while the heat transporting refrigerant would betraveling from the top to the bottom in the cooling mode, and from thebottom to the top in the heating mode, thereby providing maximum heattransfer ability and efficiency.

While submerged heat exchange tubing may be placed within a protectivepolyethylene covering, preferably one of a protective titanium or Grout111 covering would be utilized, as polyethylene has a relatively poorheat transfer rate of only 0.225 BTUs/Ft. Hr. degrees F.

13. A DX system may be utilized where the sub-surface heat exchangetubing is installed under water. When in moving water, such as at leastone of a stream, a creek, a river, and a tidal area, or the like, a DXsystem with refrigerant transport heat exchange tubing in moving waterneeds only 40 feet per ton to operate at design system tonnage capacity,with 60 feet per ton being preferred with a design safety margin. Theheat exchange tubing should be exposed to the water via at least one ofan extended line, a looped line, a coiled line, and a spiraled, spreadapart, and a looped line, always with the heat exchange line at adownwardly sloped elevation to a connecting liquid line at thebottom/distal end.

The heat exchange tubing should preferably be comprised of ¾ inch O.D.refrigerant grade copper tubing, or the like, for use in conjunctionwith up to a 30,000 BTU compressor. The heat exchange tubing shouldpreferably be comprised of ⅞ inch O.D. refrigerant grade copper tubing,or the like, for use in conjunction with a 31,000 BTU compressor up toan 83,000 BTU compressor.

The connecting liquid line, which will travel from the distal and lowestend of the larger heat exchange tubing back to the system's compressorunit, should be comprised of ⅜ inch O.D. refrigerant grade coppertubing, or the like, for use in conjunction with up to a 30,000 BTUcompressor. The connecting liquid line, which will travel from thedistal and lowest end of the larger heat exchange tubing back to thesystem's compressor unit, should be comprised of ½ inch O.D. refrigerantgrade copper tubing, or the like, for use in conjunction with a 31,000BTU compressor up to an 83,000 BTU compressor.

Alternately, the heat exchange tubing could be installed with finnedtubing within a containment box made of a corrosive-resistant material,such as at least one of titanium, Grout 111, polyethylene, and the like,to prevent damage from corrosive elements in the surrounding water andto prevent damage form micro-organisms living in the surrounding water.For example, some micro-organisms in seawater eat stainless steel.Therefore, the containment box would not be comprised of stainless steelin seawater. Preferably, such a containment box would be filled with anon-corrosive fluid, such as pure water or the like, and would have anexpanded top portion and an expanded bottom potion to facilitate thecollection and transfer of heat to the surrounding water (the warmestwater would naturally rise to the top of the containment box and thecoolest water would naturally fall to the bottom of the containment boxin both the cooling mode and in the heating mode, all while the heattransporting refrigerant (within the finned refrigerant heat transporttubing within the containment box) would be traveling from the topportion of the finned tubing to the bottom portion of the finned tubingwithin the containment box in the cooling mode, and from the bottomportion of the finned tubing to the top portion of the finned tubing inthe heating mode, thereby providing maximum heat transfer ability.

While submerged heat exchange tubing may be placed within a protectivepolyethylene containment box covering, preferably a containment boxcomprised of at least one of titanium and Grout 111 would be utilized,as polyethylene has a relatively poor heat transfer rate of only 0.225BTUs/Ft. Hr. degrees F. However, protective piping, within which boththe un-fined vapor refrigerant transport line and the liquid refrigeranttransport line (traveling to and from the heat exchange tubing, withfins, within the containment box) may be placed, may be comprised of apolyethylene pipe, or the like, as heat transfer in the protective pipearound the refrigerant transport lines to/from the containment box isnot of critical importance. Insulation would preferably be placed aroundall refrigerant transport tubing situated above the water.

When in salt water and/or in water that is at least one of corrosive andabrasive to copper or other refrigerant transport tubing, therefrigerant transport tubing must be situated within a protectiveencasement, such as at least one of Grout 111, titanium, polyethylene,and a non-corrosive fluid filled pipe, and the like. The protectiveencasement may be comprised of a shell. In the alternative, theprotective encasement may be comprised of a solid material, such asGrout 111. Grout 111 is highly heat conductive (1.4 BTUs/Ft.Hr. DegreeF.), weighs about 18.5 pounds per gallon, is virtually water impervious,and cures as a solid cementitious grout. A Grout 111 protectiveencasement will, therefore, act as both a good heat transfer agent andas an anchor for the larger diameter, downwardly sloping, heat exchangerefrigerant vapor transport tubing, coupled at the lower distal end tothe smaller diameter liquid refrigerant transport tubing. The portionsof the refrigerant transport tubing above the water would be insulated.

14. How to offset water buoyancy in a DWDX system installation. Whenwater is encountered, the buoyancy of the insulated liquid line in a DXsystem will require the addition of additional adding weight to offsetthe buoyancy. The weight needed to offset the buoyancy of a ⅜ inch O.D.liquid refrigerant transport line comprised of copper, surrounded by aclosed cell type insulation with a ¾ inch thick wall, together with a ¾inch O.D. un-insulated vapor refrigerant transport line, being droppedinto a water-filled well/borehole, is about 1.5 pounds per foot ofdepth. Preferably steel, or the like, rods are used to add weight in aDX system. Weight may be added via taping/tying maximum five footsegments of maximum 2 inch diameter steel tubing (2 inch diameter weighs10.68 pounds per foot . . . 1.75 inch diameter weighs 8.18 pounds perfoot . . . 1.5 inch diameter weighs 6.01 pounds per foot) or smallerre-bar, or the like, to the line set as needed. Prior to attachment, thesteel, or the like, tubing should preferably be wrapped in a protectivewrapping, such as shrink wrap, tape, or the like, so as to protect thecopper refrigerant transport tubing. The taping/tying of the maximumfive foot long segment to the copper tubing should be done at the topand at the bottom of the segment only, so as to only place a minimum ofheat transfer inhibiting tape, or the like, around the vapor refrigeranttransport line used for geothermal heat transfer, and so as to permitsome flexibility between the segments during installation into awell/borehole that may not be perfectly straight, so as to avoidjamming.

DX systems utilizing a ⅜ inch O.D., or less, liquid refrigerant line,and utilizing a ¾ inch O.D., or less vapor refrigerant line, typicallyrequire 4.5 inch to 6 inch diameter wells/boreholes, so as to provideenough room to easily insert the refrigerant transport lines, as well asthe insulation surrounding the liquid line. A trimme tube is typicallyused to fill the annular space remaining within the well with a grout.The trimme tube is typically close to the same weight as water, and hasan open lower distal end. Thus, the trimme tube fills with water as therest of the closed loop refrigerant tubing and insulation are allinserted into the water filled well/borehole.

Add as many segments of steel tubing as necessary to offset thebuoyancy. However, there must not be a vertical gap between the segmentsbeing added. If a vertical gap exists, which is historically permissiblewhen plastic polyethylene pipe is used to transport water as ageothermal heat exchange fluid, the soft copper refrigerant transporttubing in a DX system application could be crimped/damaged duringinstallation. Thus, in a DX system application, it is critical that thesegments must be placed directly above one another, or slightlyoverlapped. A maximum of 5 foot long segments, although 4 foot longsegments are preferred, should be used in a DX system application so asto avoid damaging the copper refrigerant transport tubing, and so as toavoid jamming during the insertion, when the well/borehole is notperfectly straight, as it seldom is. While longer segments may be usedwhen water-filled polyethylene pipe is used as a heat transfer agent,since plastic pipe is typically more flexible than copper tubing, in aDX system application, segments should preferably be limited to amaximum of 5 foot lengths, with a maximum of 4 foot lengths beingpreferable.

For example, one will need to add 1.5 pounds of additional weight perfoot of water-filled borehole to offset the buoyancy factor created by a¾ inch wall closed cell insulation surrounding a ⅜ inch O.D. refrigeranttransport liquid line. Thus, if 2 inch diameter steel tubing is used fora weight segment, one may need up to 8.5 segments that are 4 feet longeach to offset the buoyancy in a 300 foot deep well. If 1.75 inchdiameter steel tubing is used, one may need up to 11 segments that are 4feet long each. If 1.5 inch diameter steel tubing is used, one may needup to 15 segments that are 4 feet long each. When water is encountered,one should drop the copper tubing as far as possible via its own weight,and then securely tape or shrink wrap on segments of steel tubing onlyas periodically necessary to continue the installation to its fullwell/borehole design depth, which depth is typically at least onehundred feet per ton of system design capacity.

An alternative method of offsetting buoyancy would be to drop the coppertubing as far as possible via its own weight, using a 1.25 inch (not a 1inch) trimme tube and then slowly fill the grout line with Grout 111. Asthe Grout 111 fills the trimme tube, the weight of the grout in a 1.25inch diameter trimme tube will push the copper tubing down, displacingthe water as it goes. However, a plug must be placed in the bottom ofthe trimme tube that will be pulled out as the trimme tube is pulled upoff the liquid and vapor refrigerant transport lines coupled togetherwithin the Torpedo at the lower distal end. The plug would be tied tothe eyebolt extended from the cementitious grout filling the Torpedounit, so that the plug secured to the eyebolt, which eyebolt is securedto the Torpedo, prevents the plug from traveling up as the trimme tubeis pulled up and away from the bottom of the well during actualgrouting. However, as filling a trimme tube with Grout 111 is verycumbersome, the typically preferred method of off-setting buoyancy wouldbe to as previously described hereinabove. Consequently this describedalternate method will not be shown herein in the drawings.

15. Plastic Coating for Copper Tubing.

Apply a relatively thin plastic, or the like, coating to the exteriorsurface of sub-surface copper, or the like, tubing used for DXheating/cooling systems to assist in preventing damage from corrosivesoils/water/materials. Conventional plastic coatings forunderground/underwater copper tubing is comprised of a thick, strong,coating, typically comprised of a 0.70 mm, or greater, thick coating,which is also designed to be strong enough to optionally decrease thewall thickness of the copper so as to lower copper costs. However, sucha thick plastic coating inhibits heat transfer in a DX system design.Consequently, a thinner walled plastic coating would be preferable for aDX system underground/underwater/within materials (such as concrete orthe like) application, with the coating being only 0.60 mm thick, orless. The plastic coating could be comprised of at least one ofpolyethylene, teflon, or the like. A 0.60 mm thick, or less plasticcoating of polyethylene, for example, will typically not inhibit heattransfer by any more than an approximate 2% degradation, which isacceptable in a typical DX system design, as safety margins in excess of2% are typically always incorporated into sub-surface heat exchange linelength exposure distances.

For a more uniform heat absorption/rejection rate, along the entirelength of a DX system sub-surface refrigerant transport heat exchangetube, with a plastic, or the like, coated exterior surface, it would bepreferable to periodically decrease/increase the thickness of thecoating. The thicker the coating, the slower the heatabsorption/rejection rate, and the thinner the coating, the faster theheat absorption/rejection rate.

16. Double Direct Exchange System.

In the heating mode, any direct exchange geothermal heat acquisitiontubing array may be used, preferably those taught by Wiggs. However,instead of transferring the heat acquired from the geothermal source toan air handler with an electric fan, or to a hydronic system with awater circulating pump, the heat would preferably be transferreddirectly to the air or water desired to be heated via convective heattransfer through a secondary heat exchange loop without the necessity ofa secondary power draw, such as that occasioned by an electric fan or awater pump. The use of a sub-surface DX geothermal convective heatexchange system in conjunction with a secondary DX convective heatexchange system is hereby terms a “double direct exchange system”.

For a double direct exchange system used to heat concrete swimmingpools, or the like, insulation should preferably be placed around thebase and sides of the pool, and the secondary heat exchange loop shouldpreferably be placed between the insulation and the water containmentmeans, such as within the pool's concrete shell for example.

Preferably, so as to avoid any undue wear on the heat exchange tubingwithin the concrete shell of the pool, the heat exchange tubing would becoated with a plastic coating, thick enough to protect the tubing, butthin enough so as not to unduly inhibit heat transfer. In this regard,in order to enhance even heat exchange, decreasing thicknesses of theplastic coating would be utilized.

Preferably, whether coated with plastic or not, all U bends in the heatexchange tubing within the concrete would be insulated with a closedcell foam insulation, so as to provide room for expansion/contraction atthe ends of the tubing where the tubing was not confined by concrete.

Alternatively, the heat exchange tubing would be placed on top of theinsulation around the base and sides of the pool, and then covered witha thin plastic sheet. The concrete would then be poured on top of theplastic sheet, with the heat exchange tubing below, and with theinsulation between the tubing and the ground. This would enable the

In such a secondary heat exchange loop, the heat exchange tubing(typically copper, or the like) may be comprised, for example, of anarray of ¼ inch 100 foot long tubes that are one of horizontallyinclined or sloped, with the slope extending in the direction of therefrigerant flow in the heating mode, so that the condensing refrigerantvapor, as it rejects its heat into the concrete/pool water, will drainto a lower elevation via gravity flow.

Such a system may be operated in a reverse cycle to chill, or cool, thewater in a swimming pool. However, a reverse cycle operation of a doubledirect exchange system operating within the atmosphere of a structurewould require a condensate drainage system to collect and remove theinterior moisture condensing any exposed interior air heat exchangetubing.

In any double direct exchange system, if an array of ¼ inch O.D.refrigerant grade refrigerant transport tubing is utilized as thesecondary heat exchange loop, one should preferably utilize an array of6 such ¼ inch O.D. tubes per ton of maximum heating/cooling systemdesign capacity, where 1 ton equals 12,000 BTUs.

Additionally, in a double direct exchange system, the secondary heatexchange loop could optionally be comprised of at least one, optionallyfinned, vapor refrigerant transport tube/line. The at least one,optionally finned, vapor refrigerant transport tube/line would becoupled to at least one liquid refrigerant transport line at the distalend of the secondary heat exchange loop, with the liquid line making atleast a 1 inch, and preferably at least a 6 inch, vertically anddownwardly oriented U bend prior to coupling to the vapor line at thehigher elevation. The U bend should preferably be at the lowest point ofthe entire secondary heat exchange loop, and the vapor line must be oneof at least horizontally oriented and downwardly sloped to the U bend.

Preferably, such heat exchange loops would be comprised of a ¾ inch O.D.copper refrigerant grade vapor refrigerant transport line, or the like,that is at least 100 feet long per ton of system design capacity, withat least 120 feet long per ton being preferred, when the vapor line isembedded in a heat conductive material such as cement, concrete, or thelike.

Preferably, such heat exchange loops would be comprised of at least 5⅜inch O.D. copper refrigerant grade vapor refrigerant transport lines, orthe like, that are at least 100 feet long per ton of system designcapacity, with at least 120 feet long per ton being preferred, when thevapor line consists of finned tubing solely exposed to the interior air.The vapor refrigerant transport line may optionally be distributed intomultiple smaller lines that have a total of the same equivalent interiorvolume of refrigerant.

In a double direct exchange system, the secondary heat exchange looptubing should be comprised of one ¾ inch O.D. refrigerant grade coppertubing, or the like, or of multiple smaller tubes with a totalequivalent interior diameter, for use in conjunction with up to a 30,000BTU compressor. The heat exchange tubing should be comprised of one ⅞inch O.D. refrigerant grade copper tubing, or the like, or of multiplesmaller tubes with a total equivalent interior diameter, for use inconjunction with a 31,000 BTU compressor up to an 83,000 BTU compressor.

In a double direct exchange system secondary heat exchange loop, theconnecting liquid line portion of the secondary loop, which will travelfrom the distal end of the larger heat exchange tubing back through thesystem's compressor unit to the sub-surface geothermal evaporator,should be comprised of ⅜ inch O.D. refrigerant grade copper tubing, orthe equivalent, for use in conjunction with up to a 30,000 BTUcompressor. In a double direct exchange system secondary heat exchangeloop, the connecting liquid line portion of the secondary loop, whichwill travel from the distal end of the larger heat exchange tubing backthrough the system's compressor unit to the sub-surface geothermalevaporator, should be comprised of ½ inch O.D. refrigerant grade coppertubing, or the equivalent, for use in conjunction with a 31,000 BTUcompressor up to an 83,000 BTU compressor.

Lastly, in a double direct exchange system, in various applications, itwould be preferable to at least one of distribute the heat in theheating mode and absorb/remove the heat in the cooling mode in arelatively uniform manner throughout the secondary portion of the doubledirect exchange system. This is accomplished by insulating the secondaryportion of the heat transfer tubing with insulation of a decreasinginsulation value. Thus, the first portion of the secondary heat exchangetubing would be insulated the heaviest, with the insulation thicknessdecreasing until the last portion of the tubing is reached, which wouldbe un-insulated. For example, one may coat the first portion of thesecondary heat exchange tubing with a 1.5 mm thick plastic polyethylenecoating, with the thickness of the coating at least one of uniformlydecreasing and periodically decreasing throughout the length of thesecondary heat exchange tubing, with the final portion of the secondarytubing having no coating at all. Otherwise, a significant majority ofthe heat, via such secondary heat exchange tubing, will be transferredthrough the first portion of the secondary tubing, potentiallyoverheating the first portion of the area to be heated and leaving thefinal portion of the area to be heated without adequate heat.

16. Swimming Pool Application

A double direct exchange system, as described above, would be an idealapplication for heating a swimming pool, or the like.

In such an application, so as to avoid any undue wear on the heatexchange tubing within the concrete shell of the pool, the heat exchangetubing would be coated with a plastic coating, thick enough to protectthe tubing, but thin enough so as not to unduly inhibit heat transfer.In this regard, in order to enhance even heat exchange, decreasingthicknesses of the plastic coating would be utilized.

Additionally, and/or alternately, in such an application, thesub-surface heat exchange tubing within the concrete shell of the poolwould typically have U bends, which U bends should preferably besurrounded with a closed cell insulation. The insulation would preventthe concrete from restricting the copper tubing fromexpanding/contracting at the U bends, where the most stress wouldtypically occur, as the tubing within the insulation would be free toexpand/contract as necessary due to fluctuating temperatures, therebypreventing undue wear and tear on the tubing.

Alternately and/or additionally, in such an application, a thin plasticsheet may be placed under the floor and behind the concrete, or thelike, walls of the pool. At least one of under and behind the thinplastic sheet would be the sub-surface heat exchange tubing, such asused in a DX heating/cooling system. At least one of under and behindthe tubing would be a layer of insulation. The insulation helps insurethe bulk of the heating/cooling effect of the DX system is transmittedto the water in the pool through the tubing, and is not lost into thesurrounding ground. The plastic sheet, between the tubing and theconcrete, prevents any restriction imposed upon the potentialexpansion/contraction of the tubing under varying temperatureconditions, as well as prevents any exposure of the tubing to anypotentially corrosive elements by means of the concrete, or the like,shell of the pool.

17. Ground Loop Test Procedures.

Once installed, a sub-surface ground loop in a DX system is typicallygood. However, if an unknown kink in a line has occurred during system,or if a pebble or some other debris has accidentally fallen into theline set during installation, such restriction could impair systemoperation. The only solution would be to replace the well once thesystem had been fully installed and operation had been found to beimproper. In order to avoid such an expense in ascertaining a blockedline in a sub-surface line set, at least one of two tests may beconducted prior to grouting/covering the sub-surface line, so that if arestriction is found, the sub-surface line set may be easily removed andrepaired prior to grouting and/or backfilling.

One test would be to charge the line with dry nitrogen and to time therelease. For example, a restricted 300 foot deep well, with a ⅜ inchO.D. liquid line and a ¾ inch O.D. vapor line, with a 160 dry nitrogencharge, would experience an approximate 4 psi higher charge level at theend of a 30 second pressure release than would a clear and unrestrictedline set in the same well.

Another similar pressure release test would be to charge the sub-surfaceline set with 50 pounds, for example, of dry nitrogen and then releasethe charge through the liquid line for one minute only. If the lines arenot restricted, in a one minute pressure release period, there willtypically be: a 30 psi to 35 psi pressure drop in an approximate 195foot long line set; an approximate 20 psi to 32 psi pressure drop in anapproximate 255 foot long line set; and an approximate 18 psi to 25 psipressure drop in an approximate 255 foot long line set.

A second test option would be to drop a small lightweight plastic ball,or the like, into one of the lines at the above-surface end of the lineset. Such a ball would preferably be small enough to roll through the Ubend at the bottom and/or distal end of the sub-surface refrigerantloop, but would be large enough to be blocked by any significantrestriction and/or kink in the line set. The ball would be blown out ofthe line set by means of a relatively small amount of dry nitrogen, orthe like, such as only 50 psi. If the ball could not be blown out, arestriction would be evidenced. In such event, the dry nitrogen pressurewould be blown into the opposite line to retrieve the ball and the testcould be repeated. If the results were the same via two tests, the lineset should be retrieved, repaired, and re-inserted prior to groutingand/or backfilling. A preferable plastic ball for testing in a ⅜ inchO.D. liquid refrigerant transport line would be a 6 millimeter, 0.24caliber, plastic ball, such as that used in pellet guns, distributed byAirStrike, of P.O. Box 220, Rogers, Ariz., USA, 72757. such a plasticball is lightweight enough to be easily blown out of a good andunrestricted line set, is tough enough not to crumble or break intopieces during testing, is large enough to become stopped by asignificant restriction, and is small enough to pass through ⅜ inch O.D.tubing that has been cut with tubing cutters, but not reamed out.

A preferable testing procedure would consist of dropping such a 6 mmplastic ball, into the top open end of the vapor refrigerant transportline extending from the top of the well, and waiting for about one fullminute per 300 feet of depth, so as to insure the ball falls to thebottom. Next, a pressure hose would be attached and taped/sealed to thetop end of the vapor refrigerant transport line, and a net, a sock, orthe like, would be secured to the top open end of the smaller diameterliquid refrigerant transport line exiting the top of the well/borehole.50 psi of pressure, preferably consisting of dry nitrogen, would then besent into the vapor refrigerant transport line via the pressure hose.The other end of the pressure hose would be attached to a refrigerantgauge set also attached to a pressurized container of dry nitrogen,which container supplies the pressurized nitrogen for the test. If thesub-surface refrigerant transport tubing is not restricted, the plasticball will be pushed up and out of the liquid refrigerant transport line,into the net or sock, at a rate of about 25 feet per second, plus orminus 4 feet per second.

A 6 mm plastic ball would be preferable for use with a ⅜ inch O.D.liquid refrigerant transport line, which is coupled to a larger O.D.vapor refrigerant transport line, such as a ¾ inch O.D. vapor transportline, at the lower distal end of the sub-surface refrigerant transportloop. Such a 6 mm sized plastic ball is large enough to be stopped byany significant restriction, but is small enough to pass through anyminor kink in the refrigerant lines, and is small enough to pass throughany refrigerant segment that has been cut with refrigerant tubingcutters and accidentally not reamed out.

If the liquid refrigerant transport line is larger than a refrigerationgrade ⅜ inch O.D. line, with a 0.032 inch wall thickness, then aproportionately larger sized plastic ball needs to be used. If theliquid refrigerant transport line is smaller than a refrigeration grade⅜ inch O.D. line, with a 0.032 inch wall thickness, then aproportionately smaller sized plastic ball needs to be used.

Preferably, the test will be conducted before the well is grouted, sothat if there is a problem, the tubing can be withdrawn from the welland repaired prior to grouting. This simple test can save thousands ofdollars and time, otherwise lost if a refrigerant transport line is onlyfound to be restricted by means of the traditional DX system operationaltest, after full job completion. A defective/restricted line set, afterfull job completion, can only be corrected by means of installing acomplete new replacement line set, within a newly drilled and groutedwell.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 a side view of a simple and basic version of a deep well directexchange/expansion geothermal heat pump system operating in a coolingmode.

FIG. 2 is a side view of an example of a liquid line segment.

FIG. 3 is a side view of an example of an air handler.

FIG. 4 is a side view of an example of a DWDX system.

FIG. 5 is a side view of an example of a copper tubing DWDX systeminstallation spool.

FIG. 6 is a side view of an example of a segment of the pre-assembledline set.

FIG. 7 is a side view of an example of a segment of a Torpedo unit.

FIG. 8 is a top view of an example of a near-surface, but sub-surface,DX trench geothermal heat exchange system.

FIG. 9 is a side view of an example of a larger diameter vaporrefrigerant transport line.

FIG. 10 is a side view of an example of the distal end of a near surfaceDX trench system.

FIG. 11 is a top view of an example of a multiple sub-surface geothermalheat exchange loops.

FIG. 12 is a side view of an example of sub-surface heat exchange tubinginstalled under water.

FIG. 13 is a top view of an example of sub-surface heat exchange tubing.

FIG. 14 is a top view of an example of sub-surface heat exchange tubing.

FIG. 15 is a top view of an example of sub-surface heat exchange tubing.

FIG. 16 is a side view of an example of a larger diameter refrigeranttransport heat exchange tubing with attached fins installed within acontainment box.

FIG. 17 is a side view of an example of refrigerant transport tubingwithin a protective encasement.

FIG. 18 is a side view of an example of a closed cell type insulatedliquid refrigerant transport line and larger diameter, un-insulated,vapor refrigerant transport line entering a well/borehole.

FIG. 19 is a side view of an example of a coating applied to theexterior surface of sub-surface heat exchange tubing.

FIG. 20 is a side view of an example of a sub-surface refrigeranttransport heat exchange tube with varying thicknesses of a coating.

FIG. 21 a side view of an example of a double direct exchangeheating/cooling geothermal heat pump system operating in a cooling mode.

FIG. 22 is a side view of an example of sub-surface heat exchange tubingwithin concrete.

FIG. 23 is a side view of an example of a floor/wall structure.

FIG. 24 is a side view of an example of an apparatus for an integritytesting method.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The following detailed description is of the best presently contemplatedmode of carrying out the invention. The description is not intended in alimiting sense, and is made solely for the purpose of illustrating thegeneral principles of the invention. The various features and advantagesof the present invention may be more readily understood with referenceto the following detailed description taken in conjunction with theaccompanying drawings.

Referring now to the drawings in detail, where like numerals refer tolike parts or elements, there is shown in FIG. 1 a side view of a simpleand basic version of a deep well direct exchange/expansion geothermalheat pump system operating in a cooling mode.

A refrigerant fluid (not shown) is transported, by means of acompressor's 1 force and suction, inside a larger diameter un-insulatedsub-surface refrigerant vapor transport/heat exchange line tube 11,which is located below the ground surface 4 within a heat conductive,watertight pipe 5. A smaller diameter sub-surface liquid refrigeranttransport line tube 2, which is surrounded by insulation 3, also extendswithin the heat conductive, watertight pipe 5 all the way to the pipe'ssealed lower end/bottom 6, which pipe 5 has been inserted into a deepwell borehole 7 all the way to the bottom 8 of the deep well borehole 7.As the sub-surface liquid refrigerant transport tube 2 reaches thesealed pipe bottom 6, the sub-surface liquid tube 2 forms a U bend 9,which constructively acts as a liquid refrigerant trap, and thesub-surface liquid tube 2 is thereafter coupled, with a refrigerant tubecoupling 10, to the larger diameter un-insulated sub-surface refrigerantvapor transport/heat exchange tube 11. As the refrigerant fluid flowsdown within the larger diameter un-insulated sub-surface refrigeranttransport/heat exchange line tube 11, on its way to the smaller diametersub-surface liquid refrigerant transport line tube 2, the refrigeranttransfers heat into the cooler natural earth 23 geothermal surroundingsbelow the ground surface 4 and is condensed into a cool liquidrefrigerant form, as heat always travels to cold.

The cooled refrigerant fluid, which has rejected excessive heat into theearth 23 below the ground surface 4, condenses into a mostly liquidrefrigerant form and travels up from the U bend 9 near/at the sealedpipe's lower end/bottom 6 into an exterior refrigerant transport liquidline tube 25, which is surrounded by insulation 3, through an exteriorstructure wall 24, and into interior liquid refrigerant transport linetubing 27. The liquid refrigerant then travels around and through thefirst pin restrictor 29 (in the heating mode, which is not shown as thereverse cycle mode of operation is well understood by those skilled inthe art, the refrigerant flows in a reverse direction only through thehole in the center of the pin restrictor, and not additionally aroundthe pin, so that the flow of the refrigerant is restricted and metered,as is well understood by those skilled in the art) within the firstsingle piston metering device 20, through the receiver 18, whichautomatically adjusts the optimum amount of refrigerant charge flowingthrough the system in each of a heating mode and a cooling mode. In thecooling mode, most all of the refrigerant flows out of the bottom 35 ofthe receiver 18, while in the heating mode (not shown), when therefrigerant is flowing in the opposite direction through the receiver 18(as is well understood by those skilled in the art), the receiver 18fills with liquid to a predetermined containment point 36, which point36 is calculated for maximum capacity so as to contain one pound ofrefrigerant for every forty feet in depth of the liquid line 2 withinthe deep well/borehole 7. However, for optimal efficiency, the receiver18 fills with liquid to a predetermined containment point 36, whichpoint 36 is calculated for maximum capacity so as to contain one poundof refrigerant for every fifty feet in depth of the liquid line 2 withinthe deep well/borehole 7. The said respective one pound per 40 feet, orper 50 feet, containment point 36 design within the receiver 18 ispreferably calculated based upon the depth of a ⅜ inch O.D. liquidrefrigerant grade transport line 2, situated within a well/borehole 7,within a DWDX system design, or the equivalent thereof when other lineset sizes are utilized, exclusive of the trenched line(s) to/from thewell(s) (not shown herein but well understood by those skilled in theart) and exclusive of any other DX system refrigerant containmentcomponents.

In the heating mode, when the refrigerant flow travels through the firstsingle piston metering device 20, as is well understood by those skilledin the art even though not shown herein, the optimum sizing of the firstpin restrictor 29 within the first single piston metering device 20, isas explained and set forth under Summary Of Invention, Number 2,hereinabove, which is incorporated herein by reference. Although in atypically cooling to heating season period, the ground, which has beenabsorbing rejected heat all summer, will typically cool enough to permitinstant DX system heating mode operation with only a properly sizedheating mode first pin restrictor 29, if the seasonal change isextremely abrupt and fast, a pressure regulated heating mode refrigerantby-pass vale 41 within a heating mode by-pass line 42 around the heatingmode pin restrictor 29 may be necessary so as to permit instant systemheating mode operation without the system tripping off via its safetyhigh pressure cut off switch 43 (the operation of a pressure regulatedvalve and of a high pressure cut-off switch are well understood by thoseskilled in the art and are therefore not shown in detail herein). Toaccomplish this optional heating mode protective means, one shouldpreferably add a heating mode by-pass pressure regulated valve 41, alsoreferred to as an automatic expansion valve (“AXV”), so as to assisttransition from the cooling mode to the heating mode so that the valveopens to a specifically designed interior diameter, as is more fully setforth hereinabove under Summary Of Invention, Number 3, hereinabove,which is incorporated herein by reference.

The refrigerant then flows through the self-adjusting thermal expansionvalve 16, as well as through a thermal expansion valve by-pass line 17,which line 17 contains a second single piston metering device 37, alsoknown as a thermal expansion pin restrictor device. The thermalexpansion valve by-pass line 17 and second pin restrictor 38 within thesecond single piston metering device 37 permits enough refrigerant flowto by-pass the self-adjusting thermal expansion valve 16 so as to enablesystem operation in the cooling mode at the beginning of the coolingseason when the ground is very cold, but does not permit enoughrefrigerant to by-pass the self-adjusting thermal expansion valve 16 soas to materially impair system operation when the ground warms up bymeans of heat rejection during the warm summer months. The optimumsizing of the second pin restrictor 38 within the second single pistonmetering device 37, all within the by-pass line 17, is as explained andset forth under Summary Of Invention, Number 4, hereinabove, which isincorporated herein by reference.

The refrigerant fluid next flows through interior located finned heatexchange tubing 14, also commonly called an air handler, with anadjacent fan 15 designed to blow hot interior air over the coolerrefrigerant fluid within the finned heat exchange tubing 14 so as enablethe cooler refrigerant to absorb and remove excess heat from theinterior air.

The warmed refrigerant fluid, having absorbed excessive heat from theinterior air, is transformed into a mostly vapor state, and then flowsthrough an interior located reversing valve 12, into an accumulator 13,which catches and stores any liquid refrigerant which has not fullyevaporated, and then travels into the compressor 1. The compressor 1compresses the cooler refrigerant vapor into a hot refrigerantgas/vapor. The hot refrigerant vapor then travels, by means of the forceof the compressor 1, through the oil separator 30. The oil separator 30has a small oil return line 31 that returns oil, which has escaped fromthe compressor 1, to the suction line portion 32 of the interior vaporrefrigerant transport line tubing 28, which suction line portion 32 islocated prior and proximate to the accumulator 13, by means of oilreturn line alternate route A 33. In an alternative, the oil could bereturned, by means of the oil return line 31, directly into theaccumulator 13, as is shown herein by means of oil return line alternateroute B 34. The refrigerant fluid then travels through the interiorlocated reversing valve 12, back through the exterior structure wall 24,through the exterior refrigerant transport vapor line tube 26, which issurrounded by insulation 3, and back into the larger diameterun-insulated sub-surface refrigerant vapor transport/heat exchange linetube 11, which is located below the ground surface 4, where thegeothermal heat exchange process is repeated.

All above ground surface 4 interior liquid refrigerant transport linetubing 27, and all above ground surface 4 interior vapor refrigeranttransport line tubing 28, are fully insulated with rubatex, or the like,as is common in the trade, which is well understood by those skilled inthe art and, therefore, is not shown herein.

So as to avoid non-heat conductive air gaps, the remaining interiorportion of the heat conductive watertight pipe 5, located below theground surface 4, is filled with a heat conductive fluid mixture ofwater and anti-freeze 21. For a similar purpose, the space below theground surface 4, between the exterior wall of the pipe 5 and theinterior wall of the deep well borehole 7, is filled with a heatconductive grout 22, which is in direct thermal contact with theadjacent and surrounding earth 23.

An optional low pressure cut-off switch 19 is also shown for a secondarymeans of compressor 1 shut-off in the event of a refrigerant leak orother low pressure operational event. If used, the low pressure cut-offswitch 19 should be set/designed not to shut off the compressor 1 unlessthere has been a continuous minimum of 10 minutes of system operationunder pressure conditions below the requisite minimum. However, eventhough shown herein, it is preferably unnecessary to employ the use of asecondary low pressure cut off switch 19, since the compressor's owninternal safety cut-off mechanism will shut the compressor off should itbecome overheated due to an inordinate period of operation under too lowof a refrigerant pressure condition. Thus, in a preferable design, thelow pressure cut of switch 19 shown here would simply be eliminated.

In lightening prone areas, such as the State of Florida, a designimprovement to help prevent attracting lightening to underground coppertubing would consist of placing a non-electrical conductive covering 39,such as a rubber mat or the like, over the top of the well/borehole

The operation of a low pressure cut-off switch 19, a compressor 1, anelectric powered fan 15, a self-adjusting thermal expansion valve 16,and their requisite and appropriate electrical wiring, as well as theoperation of all other system components, are well understood by thoseskilled in the art and are, therefore, neither shown nor describedherein in detail.

FIG. 2 is a side view of a liquid line segment 44. The liquid linesegment 44 is comprised of a first refrigerant flow cut-off valve 45(which is well understood by those skilled in the art), a refrigerantfilter/dryer 46 (which is well understood by those skilled in the art),an optional refrigerant transport liquid line distributor 47 (which iswell understood by those skilled in the art), and two respective heatingmode single piston metering devices 20 situated on each distributedrespective liquid refrigerant transport line 2, each of which respectiveliquid refrigerant transport lines 2 are coupled to secondaryrefrigerant flow cut-off valves 48. Smaller DX systems with 30,000 BTUdesign capacities typically require no distributor 47 and only oneheating mode single piston metering device 20, with only one secondaryrefrigerant flow cut-off valve 48, although systems with greater BTUdesign capacities typically require at least two respective heating modesingle piston metering devices 20 situated on each distributedrespective liquid refrigerant transport line 2, with respectivesecondary cut-off valves 48, as shown herein. A DX system compressor box49, containing DX system operational equipment, as more fully shown inFIG. 1 hereinabove, is shown with the liquid line segment attached.Although not fully shown herein, as is well understood by those skilledin the art, in the heating mode, the refrigerant travels from thecompressor box 49 through the liquid line assembly 44, through thesub-surface heat exchanger (not shown herein), and back into thecompressor box 49 by means of the vapor refrigerant transportlines/tubes 11. Here, since the liquid refrigerant transport lines 2 aredistributed, so are the vapor refrigerant transport lines 11 by means ofa vapor line distributor 50.

FIG. 3 is a side view of an air handler 51 (which is well understood bythose skilled in the art). Generally, an air handler 51 is comprised ofa metal box containing finned heat exchange tubing 14 and an electricpowered fan/blower 15. Here, a cooling mode TXV by-pass pressureregulated valve 52, also referred to as an automatic expansion valve(“AXV” 52), is shown to assist transition from the heating mode to thecooling mode in a DX system.

Preferably, the valve 52 is designed to open to an interior diameter ofat least the size of the actual BTU size, in thousandths, of thecompressor (the system's compressor is not shown herein, but is number 1in FIG. 1 hereinabove) in the compressor unit/box (the compressor box isnot shown herein, but is number 49 in FIG. 2 hereinabove) multiplied by0.00009, with no less than multiplied by 0.00009, and with preferably nomore than multiplied by 0.00018, to be opened when the refrigerantsuction pressure is 85 psi (plus or minus 5 psi) or less, and to beclosed when the refrigerant suction pressure is above 85 psi (plus orminus 5 psi). Match the resulting number, which will be the area of theorifice, to the closest pin size diameter if to be measured in pinrestrictor sizing (pin restrictor diameters and sizing are well known tothose skilled in the art). The lower the refrigerant pressure, thegreater the opening in the valve.

Alternately, although not as precise as individually tailored by-passvalves for each respective compressor size, a one size fits all valveopening to the actual BTU size, in thousandths, should preferably be asexplained and set forth under Summary Of Invention, Number 5,hereinabove, which is incorporated herein by reference.

The AXV valve 52 should be an external equalized valve, with a capillarytube 53 extended from the AXV valve 52 to the low pressure vapor lineexiting the air handler 51. The AXV valve 52 should preferably be anadjustable type valve that can be set to shut off at any pressurebetween 40 psi and 100 psi., with an 85 psi shut off point beingpreferable for a DX system application. A standard automaticself-adjusting thermal expansion valve 16 is also shown herein, whichstandard valve 16 is well understood by those skilled in the art.

Additionally, differing air handler 51 manufacturers utilize differingfinned tubing 14 lengths per ton of size design capacity. However, mostair handler 51 manufacturers utilize finned tubing 14 with twelve tofourteen fins per inch length. Since differing manufacturers utilizediffering lengths of tubing per ton of design capacity, it isinefficient to prescribe a certain tonnage air handler 51 to be usedwith a particular DX system BTU compressor (compressor not shown herein,but is number 1 in FIG. 1) size. Further, to optimize DX systemefficiencies, testing has shown it is impractical to match a 3 toncompressor (compressor not shown herein, but is number 1 in FIG. 1) witha 3 ton air handler 51, as most all predecessor conventional systemdesigns call for. Testing has shown that in order to optimize theefficiency of a DX system design, the air handler 51 must be sized to120% of the maximum system design load (design loads are typicallycalculated as per ACCA Manuel J, or the like, as is well understood bythose skilled in the art), and must have sixty feet per ton, plus orminus five feet, of finned ⅜ inch O.D. interior heat exchangerefrigerant transport tubing 55. Fifty-five to sixty feet of the ⅜ inchO.D. tubing 55 is preferable in the heating mode. Sixty to sixty-fivefeet of the ⅜ inch O.D. tubing is preferable in the cooling mode.

FIG. 4 is a side view of a basic and very simple Deep Well DX (a “DWDX”)system. The charging formula is for a DWDX system, or the like, usingR-410A refrigerant (the refrigerant is not shown, but circulates withinthe refrigerant transport tubing, 55 and 11, and other components of thesystem, as is well understood by those skilled in the art), with asub-surface ⅜ inch O.D. liquid refrigerant grade transport line 55 inthe well/borehole 7. The ⅜ inch line 55 is refrigerant grade copper witha 0.032 inch wall thickness. The system has a larger O.D. refrigerantgrade vapor transport line 11 in the well 7, with a sub-surface ¾ inchO.D., or larger, vapor refrigerant grade geothermal heat exchangetransport line 57 in the well/borehole 7 being preferred. The correctsystem charge is calculated by adding the sum of the following:

A. Total depth of the ⅜ inch O.D. liquid line 55 in the well 7 times0.0375 pounds. The total depth is the distance between the top 56 of thewell 7 and the liquid line U bend 9 near the bottom 8 of the well 7 inthe earth 23.

B. 50% of total length of finned ⅜ inch O.D. tubing 14 in the in the airhandler 51 multiplied by 0.0375 pounds.

C. Compressor unit/box 49 content of liquid refrigerant.

D. Add the amount of liquid refrigerant contained in the system'sfilter/dryer 46 (for example, a Parker Bi-Directional R-410A Heat PumpFilter/Dryer Model BF164-XF holds about 0.761875 pounds), exclusive ofany filter/dryer in the compressor box 49, which has already been takeninto account in the compressor unit/box 49 content.

E. Add the amount of liquid refrigerant in all liquid line ball cut-offvalves, 45 and 48 (typically about 0.05 pounds each), exclusive of theball cut-off valves, if any, in the compressor box 49, which havealready been taken into account in the compressor unit/box 49 content.

F. Measure the total liquid transport line 55 length between the top 56of the well/borehole 7, shown here at the ground surface 4, and thecompressor unit/box 49 and multiply by the full liquid refrigerantweight content of the liquid refrigerant transport line 55 in pounds.For example, multiply by 0.0375 pounds if it is a preferred ⅜ inch O.D.refrigerant grade copper line 55, but multiply by 0.06875 if it is a ½inch O.D refrigerant grade copper line. Although the liquid transportline 55 is shown here as being located between the top 56 of thewell/borehole 7 and the compressor unit/box 49 at an above groundsurface 4 location, this segment of the liquid transport line 55 istypically buried below the ground surface 4 (not shown herein but wellunderstood by those skilled in the art).

G. Measure the total liquid transport line 55 length between the airhandler 51 and the compressor unit/box 49 and multiply by the fullliquid weight content of the line in pounds. For example, multiply by0.0375 pounds if it is a ⅜ inch O.D. line 55, but multiply by 0.06875 ifit is a ½ inch O.D line.

H. For a cooling mode charge, add an additional one pound of refrigerantfor every forty feet of ⅜ inch O.D. refrigerant grade liquid line 55 inthe well for maximum system operational capacity and humidity removal.If humidity removal is not a concern, add an additional one pound ofrefrigerant for every fifty feet of ⅜ inch O.D. refrigerant grade liquidline 55 in the well for maximum efficiency.

I. If the system is designed to operate in a reverse-cycle mode (heatingand cooling), the system must have a liquid line receiver 18 that holdsthe preferred charge differential between the heating mode and thecooling mode. Additionally, the receiver 18, which should preferablyhave only one refrigerant entrance 58 and only one refrigerant exit 59,will typically have some constant amount of liquid content in itsbottom, regardless of the system operational mode, which constant amountof refrigerant, in pounds, must be added.

J. If the system is designed to operate in the heating mode with aheating mode pin expansion device/single piston metering device 20,shown here as installed between the filter/dryer 46 and the secondarycut-off valve 48, the weight, in pounds, of the liquid refrigerantcontent of the single piston metering device 20 must be added to thetotal.

The total of the appropriate above sums will equal the correct systemcharge.

To determine the optimum charge in DX systems utilizing other than ⅜inch O.D. liquid refrigerant transport lines 55 and ¾ inch O.D., orlarger, vapor refrigerant transport lines 57, the charge shouldpreferably be determined by the above formula, except the equivalentrefrigerant content of the actual interior volume of the liquidrefrigerant transport line used must be matched to the interior volumeof a ⅜ O.D. liquid refrigerant grade transport line/tube 55 as per theabove formula. For example, if multiple liquid refrigerant transportlines of a smaller interior diameter were utilized than that of a ⅜ inchO.D. refrigerant grade copper tube 55, then the content of all multiplesmaller lines must match that of the content of a system designed withat least one of one and multiple ⅜ inch O.D. refrigerant grade coppertube(s) 55. As another example, if a larger liquid refrigerant transportline was used than that of a ⅜ inch O.D. refrigerant grade copper tube,then the interior content of the larger tube must match that of thecontent of a system designed with at least one of one and multiple ⅜inch O.D. refrigerant grade copper tube(s) 55.

FIG. 5 is a side view of a copper tubing DWDX system installation spool60, with pre-assembled line sets 61 for DX system field loopinstallations. The spool 60 should preferably have at least atwenty-four inch wide holding tube 62 diameter, with both a smallerdiameter insulated 3 refrigerant transport line 2 and an un-insulated,larger diameter, refrigerant transport line 11 on the same holdingspool.

The holding spool should preferably have sides 65 extending past theouter layer 63 of the pre-assembled refrigerant transport line set 61,but with a four foot, or less, total side diameter 64 so as tofacilitate shipping on a standard four foot wide pallet.

Prior to assembly, the pre-assembled line set 61, with a cementitiousgrout-filled (preferably Grout 111) “Torpedo” unit 66 should beevacuated of air with a vacuum pump 67. The vacuum pump 67 has anexternal electrical power supply line 68 (vacuum pumps are wellunderstood by those skilled in the art), and should preferably be usedto pull at least a 250 micron vacuum. The line set 61 and Torpedo unit66 should then preferably be charged with a dry nitrogen holding chargeof 50 pounds, or the like, for shipment and installation. Charging witha 50 pound holding charge of dry nitrogen is well understood by thoseskilled in the art and is therefore not shown herein.

The 250 micron vacuum will insure there are no leaks, and the 50 poundholding charge will insure no leaks have occurred during either shipmentor installation. Both pulling the vacuum and inserting the holdingcharge of dry nitrogen are effected by means of capping 68 one of theends of at least one of the liquid refrigerant transport line 2 and thevapor refrigerant transport line 11, and then placing a schraeder valve69 (a schraeder valve is well understood by those skilled in the art) atthe end of the other for refrigeration gauge set attachment(refrigeration gauges are well understood by those skilled in the artand are therefore not shown herein). This procedure comprises asignificant time saving and efficiency improvement over the historicaland traditional method of installing sub-surface heat exchange tubing ina DX system, where the tubing is installed, sealed, and pressure testedprior to pulling a vacuum and charging, which is more time consuming andis not as trustworthy as initially pulling a vacuum. Pulling a vacuumcannot be done to 250 microns in a DX system if there is a leak, whereasa pressure test could take hours or days to reveal a very slight leak.

FIG. 6 is a side view of a segment of the pre-assembled line set 61,comprised of an insulated 3 smaller diameter liquid refrigeranttransport line 2 and an un-insulated larger diameter vapor refrigeranttransport line 11 surrounded by a spiraled fiber tape 70, or the like,so as to keep the lines, 2 and 11, together as they are lowered into thewell/borehole (not shown in this drawing, but shown as number 7 in FIG.1 hereinabove). The tape 70 must be spiraled at least once every eightto twelve inches to be effective.

FIG. 7 is a side view of a segment of a Torpedo unit 66 is comprised ofa containment tube with a rounded nose 71, which tube 71 containssmaller diameter liquid transport refrigerant transport tubing 2 andlarger diameter liquid transport refrigerant transport tubing 11, with alower liquid line 2 U bend 9, and a cementitious heat conductive groutfill material 22, preferably comprised of Grout 111, which Grout 111 isshrink and crack resistant, with a very high 1.4 BTUs/Ft.Hr. Degrees Fheat transfer rate.

FIG. 8 is a top view of a near-surface, but sub-surface, DX trenchgeothermal heat exchange system. The geothermal sub-surface heattransfer tubing, 2 and 11, is preferably comprised of equal lengths of asmaller diameter un-insulated refrigerant transport tubing 2 and of alarger diameter un-insulated refrigerant transport tubing 11, and shouldpreferably be installed with at least 100 feet of tubing per ton of themaximum heating/cooling BTU load design, as per ACCA Manuel J or thelike, where 12,000 BTUs equal one ton of heating/cooling capacity.However, 120 feet per ton is a preferred length to assist in insuringoptimum system operational efficiencies.

In such a DX trench system, one smaller diameter liquid refrigeranttransport line 2 would be coupled to one larger diameter vaporrefrigerant transport line 11 at the distal end 72 of the sub-surfaceheat exchange loop.

In such a DX trench system, the liquid refrigerant transport line 2would preferably be comprised of one 120 foot long ⅜ inch O.D.refrigerant grade copper tube, or the like, per ton of system designcapacity, with a maximum 360 foot distance per liquid line 2 segment ineach respective loop.

In such a DX trench system, the vapor refrigerant transport line 11would preferably be comprised of one 120 foot long ¾ inch O.D.refrigerant grade copper tube, or the like, per ton of system designcapacity, with a maximum 360 foot distance per vapor line segment ineach respective loop. Further, the vapor line 11 must be at least one ofhorizontally and downwardly sloped 73 toward the distal end 72, with adownward slope being preferred.

In such a DX trench system, neither the vapor refrigerant transport line11 used for subsurface heat exchange, nor the liquid refrigeranttransport line 2 used for subsurface heat exchange, would be insulated,and the respective vapor line 11 and liquid line 2, except for beingcoupled together at the distal end 72 of the loop, would be separated byat least twenty feet, with a thirty foot separation being preferablewhere land area permits. When the vapor line 11 and liquid line 2 nearone another for connection to the DX system compressor unit, each line,11 and 2, should preferably be fully insulated 3, with a closed cellinsulation 3 (such as expanded polyethylene and/or neoprene, or thelike) when they are at least within twenty feet of one another.

FIG. 9 is a side view of a larger diameter vapor refrigerant transportline 11 in a near-surface DX trench system, where the vapor line 11 ispreferably downwardly sloped.

FIG. 10 is a side view of the distal end 72 of a near surface DX trenchsystem, where the larger diameter vapor line 11 is coupled to thesmaller diameter liquid line 2. The liquid line 2 is comprised of atleast a six inch vertically and downwardly oriented U bend 9 prior tocoupling to the vapor line 11 at the at least six inch higher elevation.Both the vapor line 11 and the liquid line 2 are preferably buriedwithin the earth 23 at least two feet below the frost line from theground surface 4 in the area of system installation. The U bend 9 shouldpreferably be at the lowest point of the entire heat exchange loop, andthe vapor line 11 must be one of at least horizontally oriented anddownwardly sloped to the U bend 9. Preferably, such heat exchange loops,comprised of the joined and equal respective lengths of vapor line 11and liquid line 2, would not exceed 360 feet in length per loop.

FIG. 11 is a top view of the multiple sub-surface geothermal heatexchange loops, comprised of larger diameter vapor lines 11 coupled attheir respective distal ends 72 to respective smaller diameter liquidlines 2 in a near-surface trench system installation would preferably bejoined together by means of a vapor line distributor 50 and a liquidline distributor 47 for refrigerant transportation to the compressorunit (not shown herein, but the same as number 1 in FIG. 1) when designcapacity called for more than one 320 foot loop of exposed sub-surfacegeothermal heat transfer tubing, 2 and 11. Here, as in a single loopapplication, insulation 3 surrounds all sub-surface tubing within twentyfeet of one another.

FIG. 12 is a side view of sub-surface heat exchange tubing, 2 and 11,installed under water 75. When moving water 12 is available, such as atleast one of a stream, a creek, a river, and a tidal area, and the like,a DX system with refrigerant transport heat exchange tubing, 2 and 11,situated within the moving water 75 needs only forty feet per ton tooperate at design system tonnage capacity (as per ACCA Manuel J or thelike) with sixty feet per ton being preferred with a design safetymargin. The heat exchange tubing, 2 and 11, are shown as exposed to thewater 75 via a downwardly sloped extended larger diameter sub-surfacevapor refrigerant transport/heat exchange line/tube 11, which isconnected to a smaller diameter liquid refrigerant transport line 2, bymeans of a coupling 74, at the bottom/distal end 76 of the largerdiameter sub-surface vapor refrigerant transport/heat exchange line/tube11. The refrigerant transport lines/tubing, 2 and 11, would typically beinsulated 3, after exiting the water 75, on the way to the compressorunit (the compressor is not shown herein, but is the same as number 1 inFIG.1).

The larger diameter, sub-surface, vapor refrigerant transport tubing 11should preferably be comprised of ¾ inch O.D. refrigerant grade coppertubing, or the like, for use in conjunction with up to a 30,000 BTUcompressor. The larger diameter vapor refrigerant transport tubing 11should preferably be comprised of ⅞ inch O.D. refrigerant grade coppertubing, or the like, for use in conjunction with a 31,000 BTU compressorup to an 83,000 BTU compressor. When smaller vapor refrigerant transporttubing/lines is used (not shown herein), the interior diameter of thesmaller tubing/lines should preferably approximately equal the interiordiameter of the respective ¾ inch O.D. and ⅞ inch O.D. lines asdescribed in this paragraph matching the varying respective compressorsizes.

The connecting smaller diameter liquid refrigerant transport line 2,which will travel from the distal and lowest end 76 of the larger vaporrefrigerant transport tubing 11 back to the system's compressor unit,should preferably be comprised of ⅜ inch O.D. refrigerant grade coppertubing, or the like, for use in conjunction with up to a 30,000 BTUcompressor. The connecting liquid refrigerant transport line 2, whichwill travel from the distal and lowest end 76 of the larger vaporrefrigerant transport tubing 11 back to the system's compressor unit,should be comprised of ½ inch O.D. refrigerant grade copper tubing, orthe like, for use in conjunction with a 31,000 BTU compressor up to an83,000 BTU compressor. When smaller liquid refrigerant transport tubingis used (not shown herein), the interior diameter of the smallertubing/lines should preferably approximately equal the interior diameterof the respective ⅜ inch O.D. and ½ inch O.D. lines as described in thisparagraph with the varying respective compressor sizes.

FIG. 13 is a top view of sub-surface heat exchange tubing, 2 and 11,with a larger diameter vapor refrigerant transport line 11, coupled 74at its lowest distal end 76 to a smaller diameter liquid refrigeranttransport tube 2, all installed under the surface of water (water is notshown herein since this is a top view). Here, the larger diameter vaporrefrigerant transport line 11 is shown as being a looped, coiled, andlargely spread apart line 11. The design length and sizing of therefrigerant transport tubing, 2 and 11, should preferably be the same asthat described hereinabove in FIG. 12, which is incorporated herein byreference.

FIG. 14 is a top view of sub-surface heat exchange tubing, 2 and 11,with a larger diameter vapor refrigerant transport line 11, coupled 74at its lowest distal end 76 to a smaller diameter liquid refrigeranttransport tube 2, all installed under the surface of water (water is notshown herein since this is a top view). Here, the larger diameter vaporrefrigerant transport line 11 is shown as being a looped, coiled, andmodestly spread apart line 11. The design length and sizing of therefrigerant transport tubing, 2 and 11, should preferably be the same asthat described hereinabove in FIG. 12, which is incorporated herein byreference.

FIG. 15 is a top view of sub-surface heat exchange tubing, 2 and 11,with a larger diameter vapor refrigerant transport line 11, coupled 74at its lowest distal end 76 to a smaller diameter liquid refrigeranttransport tube 2, all installed under the surface of water (water is notshown herein since this is a top view). Here, the larger diameter vaporrefrigerant transport line 11 is shown as being comprised of a line 11with multiple U bends 9. The design length and sizing of the refrigeranttransport tubing, 2 and 11, should preferably be the same as thatdescribed hereinabove in FIG. 12, which is incorporated herein byreference.

FIG. 16 is a side view of a larger diameter refrigerant transport heatexchange tubing 11, with attached fins 77 so as to enhance heattransfer, installed within a containment box 78 made of a resistantmaterial, such as at least one of titanium, Grout 111, polyethylene, andthe like, to prevent micro-organism damage. Micro-organisms in seawatereat stainless steel. Preferably, such a containment box 77 would befilled with a non-corrosive fluid (not shown herein), such as pure wateror the like, and would have an expanded top portion 79 and an expandedbottom portion 80 to facilitate the collection and transfer of heat tothe surrounding water 75 (the warmest water would naturally rise to theexpanded top portion 79 of the containment box 77, and the coolest waterwould naturally fall to the expanded bottom portion 80 of thecontainment box 77 in both the cooling mode and in the heating mode),all while the heat transporting refrigerant (refrigerant is not shownherein, as refrigerant is well understood by those skilled in the art)would be traveling from the top portion 81 of the downwardly slopedrefrigerant transport heat transfer tubing 11, with fins 77 to thebottom portion 82 in the cooling mode, and from the bottom portion 82 tothe top portion 81 in the heating mode, thereby providing maximum heattransfer ability and efficiency.

While submerged heat exchange tubing may be placed within a protectivepolyethylene containment box 78 covering, preferably a containment box78 comprised of at least one of titanium and Grout 111 would beutilized, as polyethylene has a relatively poor heat transfer rate ofonly 0.225 BTUs/Ft. Hr. degrees F. However, protective piping 83, withinwhich both the un-fined vapor refrigerant transport line 11 and theliquid refrigerant transport line 2 (traveling to and from the heatexchange tubing 11, with fins 77, within the containment box 78) may beplaced, may be comprised of a polyethylene pipe 84, or the like.Insulation 3 would preferably be placed around all refrigerant transporttubing, 2 and 11, situated above the water 75.

FIG. 17 is a side view of refrigerant transport tubing, 2 and 11, withina protective encasement 85 of Grout 111. When in salt water 75 and/or inwater 75 that is at least one of corrosive and abrasive to copper orother refrigerant transport tubing, the refrigerant transport tubing, 2and 11, must be situated within a protective encasement 85, such as atleast one of Grout 111, titanium, polyethylene, and a non-corrosivefluid filled pipe, and the like. The protective encasement 85 may becomprised of a shell (a shell is not shown here, but is the same as theshell type containment box shown as number 78 in FIG. 16). In thealternative, the protective encasement 85 may be comprised of a solidmaterial, such as Grout 111, or the like. Grout 111 is highly heatconductive (1.4 BTUs/Ft.Hr. Degree F.), weighs about 18.5 pounds pergallon, is virtually water 75 impervious, and cures as a solidcementitious grout. A Grout 111 protective encasement 85 will,therefore, act as both a good heat transfer agent and as an anchor forthe larger diameter, downwardly sloping, heat exchange refrigerant vaportransport tubing 11, coupled 4 at the lower distal end 76 to the smallerdiameter liquid refrigerant transport tubing 2. The portions of therefrigerant transport tubing, 2 and 11, above the water 75 would beinsulated 3.

FIG. 18 is a side view of a closed cell type insulated 3 smallerdiameter liquid refrigerant transport line 2 and a larger diameter,un-insulated, vapor refrigerant transport line 11 entering awell/borehole 7, which well 7 extends beneath the ground surface 4 intothe earth 23. Here, water 75 is shown as filling the well 7 to a pointnear the ground surface 4. Therefore, additional weight needs to beadded to offset the buoyancy created by the closed cell insulation 3. DXsystems utilizing a ⅜ inch O.D., or less, liquid refrigerant line 2, andutilizing a ¾ inch O.D., or less vapor refrigerant line 11, typicallyrequire 4.5 inch to six inch diameter wells/boreholes, so as to provideenough room to easily insert the refrigerant transport lines, 2 and 11,as well as the insulation 3 surrounding the liquid line 2. Additionally,although not shown herein, a trimme tube is typically used to fill theannular space remaining within the well 7 with a grout. The trimme tubeis typically close to the same weight as water 75 and has an open lowerdistal end. Thus, the trimme tube fills with water 75 as the rest of theclosed-loop refrigerant tubing, 2 and 11, and insulation 3 are allinserted into the water 75 filled well 7. A trimme tube utilized forgrout installation is well understood by those skilled in the art.

Weight to offset the buoyancy created by the insulation 3 may preferablybe added to a DX system by means of taping/tying 90 maximum five footsegments 86 of maximum two inch diameter steel, or the like, tubing/bars(two inch diameter weighs 10.68 pounds per foot . . . 1.75 inch diameterweighs 8.18 pounds per foot . . . 1.5 inch diameter weighs 6.01 poundsper foot) or smaller re-bar, or the like, to the refrigerant transportline set, comprised of the liquid refrigerant line 2, the vaporrefrigerant line 11, and insulation 3 around the liquid line 2, asneeded. Prior to attachment by means of taping/tying 90, the steel, orthe like, tubing/bar maximum five foot long segment 86 to the coppertubing, 2 and 11, the segment 86 should preferably be wrapped in aprotective wrapping 87, such as shrink wrap, tape, or the like, so as toprotect the copper refrigerant transport tubing, 2 and 11. Add as manysegments 86 of maximum five foot long steel tubing segments 86 asnecessary to offset the buoyancy, which is dependent upon the depth ofthe water 75 within the well/borehole 7.

However, there must not be a vertical gap (not shown) between thesegments 86 being added. If a vertical gap exists, which is historicallypermissible when plastic polyethylene pipe (not shown) is used totransport water 75 as a geothermal heat exchange fluid, the soft copperrefrigerant transport tubing, 2 and 11, in a DX system application couldbe crimped/damaged during installation. Thus, in a DX systemapplication, it is critical that the segments 86 must be placed directlyabove one another 88 or slightly overlapped 89. A maximum of five footlong segments 86 should be used in a DX system application so as toavoid damaging the copper refrigerant transport tubing, 2 and 11, and soas to avoid jamming the insertion, when the well/borehole 7 is notperfectly straight, as it seldom is. While longer than five footsegments 86 may be used when water-filled polyethylene pipe (not shownherein) is used as a heat transfer agent in a water-source heat pumpsystem application (a water-source heat pump system is well understoodby those skilled in the art and is not shown herein), since plastic pipeis typically more flexible than copper tubing, 2 and 11, in a DX systemapplication, segments 86 should preferably be limited to a maximum offive foot lengths, with a maximum of four foot lengths being preferable.

The taping/tying 90 of the maximum five foot long segments 86 to thecopper refrigerant transport tubing, 2 and 11, should be done at the top91 and at the bottom 92 of the segments 86 only, so as to only place aminimum of heat transfer inhibiting tape 90, or the like, around thevapor refrigerant transport line 11 used for geothermal heat transfer,and so as to permit some flexibility between the segments 86 duringinstallation into a well/borehole 7 that may not be perfectly straight,so as to avoid jamming.

When water 75 is encountered in a well 7 during a DX system coppertubing, 2 and 11, installation, where the liquid refrigerant transportline 2 is insulated 3, one should drop the copper tubing, 2 and 11, asfar as possible via its own weight, and then securely apply a protectivewrapping 87 of tape, shrink wrap, or the like, on maximum five foot longsegments 86 of steel tubing, or the like, only as periodically necessaryto continue the installation to its full well/borehole 7 design depth,which design depth is typically at least one hundred feet per ton ofsystem design capacity.

FIG. 19 is a side view of a relatively thin plastic, or the like,coating 93 applied to the exterior surface 94 of sub-surface copper, orthe like, heat exchange tubing 95 used for DX heating/cooling systems toassist in preventing damage from corrosive soils/water/materials.Conventional plastic coatings 93 for underground/underwater copper heatexchange tubing 95 is comprised of a thick, strong, coating 93,typically comprised of a 0.70 mm, or greater, thick coating 93, which isalso designed to be strong enough to optionally decrease the wallthickness of the copper tubing 95 so as to lower copper costs. However,such a thick plastic coating 93 inhibits heat transfer in a DX systemdesign. Consequently, a thinner walled plastic coating 93 would bepreferable for a DX system where the sub-surface heat exchange tubing 95was installed in an underground/underwater/within materials (such asconcrete or the like) application, with the coating 93 being only 0.60mm thick, or less. The plastic coating 93 could be comprised of at leastone of polyethylene, tefflon, or the like. A 0.60 mm thick, or lessplastic coating 93 of polyethylene, for example, will typically notinhibit heat transfer by any more than an approximate 2% degradation,which is acceptable in a typical DX system design, as safety margins inexcess of 2% are typically always incorporated into sub-surface heatexchange line length exposure distances.

Preferably, so as to avoid any undue wear on the heat exchange tubingwithin the concrete shell of a swimming pool, or the like, the heatexchange tubing 95 would be coated with a plastic coating 93, thickenough to protect the tubing, but thin enough so as not to undulyinhibit heat transfer.

FIG. 20 is a side view of a sub-surface refrigerant transport heatexchange tube 95 with varying thicknesses of a plastic coating 93. For amore uniform heat absorption/rejection rate, along the entire length ofa DX system sub-surface refrigerant transport heat exchange tube 95,with a plastic, or the like, coated 93 exterior surface 94, it would bepreferable to periodically decrease/increase the thickness of thecoating 93. The thicker the coating 93, the slower the heatabsorption/rejection rate, and the thinner the coating 93, the fasterthe heat absorption/rejection rate. Here a refrigerant transport heatexchange tube 95 is shown as being coated with a heavy coating ofplastic 96, with a medium coating of plastic 97, and with a thin coatingof plastic 98.

In a swimming pool (not shown) heating application, for example, inorder to enhance even heat exchange throughout the pool, decreasingthicknesses of the plastic coating 93 would be utilized.

FIG. 21 a side view of a simple and basic version of a double directexchange heating/cooling geothermal heat pump system operating in acooling mode.

A refrigerant fluid (not shown) is transported, by means of acompressor's 1 force and suction, inside a larger diameter un-insulatedsub-surface refrigerant vapor transport/heat exchange line tube 11,which is located below the ground surface 4 within a heat conductive,watertight pipe 5. A smaller diameter sub-surface liquid refrigeranttransport line tube 2, which is surrounded by insulation 3, also extendswithin the heat conductive, watertight pipe 5 all the way to the pipe'ssealed lower end/bottom 6, which pipe 5 has been inserted into a deepwell borehole 7 all the way to the bottom 8 of the deep well borehole 7.As the sub-surface liquid refrigerant transport tube 2 reaches thesealed pipe bottom 6, the sub-surface liquid tube 2 forms a U bend 9,which constructively acts as a liquid refrigerant trap, and thesub-surface liquid tube 2 is thereafter coupled, with a refrigerant tubecoupling 10, to the larger diameter un-insulated sub-surface refrigerantvapor transport/heat exchange tube 11. As the refrigerant fluid flowsdown within the larger diameter un-insulated sub-surface refrigeranttransport/heat exchange line tube 11, on its way to the smaller diametersub-surface liquid refrigerant transport line tube 2, the refrigeranttransfers heat into the cooler natural earth 23 geothermal surroundingsbelow the ground surface 4 and is condensed into a cool liquidrefrigerant form, as heat always travels to cold.

The cooled refrigerant fluid, which has rejected excessive heat into theearth 23 below the ground surface 4, condenses into a mostly liquidrefrigerant form and travels up from the U bend 9 near/at the sealedpipe's lower end/bottom 6 into an exterior refrigerant transport liquidline tube 25, which is surrounded by insulation 3, through an exteriorstructure wall 24, and into interior liquid refrigerant transport linetubing 27. The liquid refrigerant then travels around and through thefirst pin restrictor 29 (in the heating mode, which is not shown as thereverse cycle mode of operation is well understood by those skilled inthe art, the refrigerant flows in a reverse direction only through thehole in the center of the pin restrictor, and not additionally aroundthe pin, so that the flow of the refrigerant is restricted and metered,as is well understood by those skilled in the art) within the firstsingle piston metering device 20, through the receiver 18, whichautomatically adjusts the optimum amount of refrigerant charge flowingthrough the system in each of a heating mode and a cooling mode. In thecooling mode, most all of the refrigerant flows out of the bottom 35 ofthe receiver 18, while in the heating mode (not shown), when therefrigerant is flowing in the opposite direction through the receiver 18(as is well understood by those skilled in the art), the receiver 18fills with liquid to a predetermined containment point 36, which point36 is calculated for maximum capacity so as to contain one pound ofrefrigerant for every forty feet in depth of the liquid line 2 withinthe deep well/borehole 7. However, for optimal efficiency, the receiver18 fills with liquid to a predetermined containment point 36, whichpoint 36 is calculated for maximum capacity so as to contain one poundof refrigerant for every fifty feet in depth of the liquid line 2 withinthe deep well/borehole 7. The said respective one pound per 40 feet, orper 50 feet, containment point 36 design within the receiver 18 ispreferably calculated based upon the depth of a ⅜ inch O.D. liquidrefrigerant grade transport line 2, situated within a well/borehole 7,within a double direct exchange heating/cooling system using a DWDXsystem design, or the equivalent thereof when other line set sizes areutilized, as one of its primary heat sources/heat sinks, exclusive ofthe trenched line(s) to/from the well(s) (not shown herein but wellunderstood by those skilled in the art) and exclusive of any other DXsystem refrigerant containment components.

In the heating mode, when the refrigerant flow travels through the firstsingle piston metering device 20, as is well understood by those skilledin the art even though not shown herein, the optimum sizing of the firstpin restrictor 29 within the first single piston metering device 20, isas explained and set forth under Summary Of Invention, Number 2,hereinabove, which is incorporated herein by reference. Although in atypically cooling to heating season period, the ground, which has beenabsorbing rejected heat all summer, will typically cool enough to permitinstant DX system heating mode operation with only a properly sizedheating mode first pin restrictor 29, if the seasonal change isextremely abrupt and fast, a pressure regulated heating mode refrigerantby-pass vale 41 within a heating mode by-pass line 42 around the heatingmode pin restrictor 29 may be necessary so as to permit instant systemheating mode operation without the system tripping off via its safetyhigh pressure cut off switch 43 (the operation of a pressure regulatedvalve and of a high pressure cut-off switch are well understood by thoseskilled in the art and are therefore not shown in detail herein). Toaccomplish this optional heating mode protective means, one shouldpreferably add a heating mode by-pass pressure regulated valve 41, alsoreferred to as an automatic expansion valve (“AXV”), so as to assisttransition from the cooling mode to the heating mode so that the valveopens to a specifically designed interior diameter, as is more fully setforth hereinabove under Summary Of Invention, Number 3, hereinabove,which is incorporated herein by reference.

The refrigerant then flows through the self-adjusting thermal expansionvalve 16, as well as through a thermal expansion valve by-pass line 17,which line 17 contains a second single piston metering device 37, alsoknown as a thermal expansion pin restrictor device. The thermalexpansion valve by-pass line 17 and second pin restrictor 38 within thesecond single piston metering device 37 permits enough refrigerant flowto by-pass the self-adjusting thermal expansion valve 16 so as to enablesystem operation in the cooling mode at the beginning of the coolingseason when the ground surrounding the deep well 7 is very cold, butdoes not permit enough refrigerant to by-pass the self-adjusting thermalexpansion valve 16 so as to materially impair system operation when theground surrounding the deep well 7 warms up by means of heat rejectionduring the warm summer months. The optimum sizing of the second pinrestrictor 38 within the second single piston metering device 37, allwithin the by-pass line 17, is as explained and set forth under SummaryOf Invention, Number 4, hereinabove, which is incorporated herein byreference.

The refrigerant fluid next flows through the secondary (the double)direct exchange convective heat transfer/refrigerant transport heatexchange tubing segment 99. Here, the secondary convective heat transfersegment 99 is shown as a distributed array of small refrigeranttransport tubes, as such a segment 99 would appear within a concrete, orthe like, wall (the concrete wall is not shown, as a concrete wall iswell understood by those skilled in the art). As would be wellunderstood by those skilled in the art, any form of DX heat exchangerefrigerant transport tubing convective heat transfer means may be usedas the secondary direct exchange convective heat transfer/refrigeranttransport heat exchange tubing segment 99, which segment is not limitedto the design as shown herein. As heat naturally flows to cold, the heatin the wall would be absorbed by the cooler refrigerant (refrigerant isnot shown as refrigerant is well understood by those skilled in the art)flowing through the secondary convective heat exchange tubing 99 withinthe wall. Thus, the cooler refrigerant would absorb and remove excessheat from the wall, which wall could be at least one of the wall of astructure, a swimming pool, and the like. The wall would, of course, beabsorbing heat from the interior air of a structure (not shown herein),from the water within a swimming pool (not shown herein), and/or fromany other heat source (not shown herein).

The warmed refrigerant fluid, having absorbed excessive heat from thesecondary convective heat exchange tubing 99, is transformed into amostly vapor state, and then flows through an interior located reversingvalve 12, into an accumulator 13, which catches and stores any liquidrefrigerant which has not fully evaporated, and then travels into thecompressor 1. The compressor 1 compresses the cooler refrigerant vaporinto a hot refrigerant gas/vapor. The hot refrigerant vapor thentravels, by means of the force of the compressor 1, through the oilseparator 30. The oil separator 30 has a small oil return line 31 thatreturns oil, which has escaped from the compressor 1, to the suctionline portion 32 of the interior vapor refrigerant transport line tubing28, which suction line portion 32 is located prior and proximate to theaccumulator 13, by means of oil return line alternate route A 33. In analternative, the oil could be returned, by means of the oil return line31, directly into the accumulator 13, as is shown herein by means of oilreturn line alternate route B 34. The refrigerant fluid then travelsthrough the interior located reversing valve 12, back through theexterior structure wall 24, through the exterior refrigerant transportvapor line tube 26, which is surrounded by insulation 3, and back intothe larger diameter un-insulated sub-surface refrigerant vaportransport/heat exchange line tube 11, which is located below the groundsurface 4, where the geothermal heat exchange process is repeated.

All above ground surface 4 interior liquid refrigerant transport linetubing 27, and all above ground surface 4 interior vapor refrigeranttransport line tubing 28, are fully insulated with rubatex, or the like,as is common in the trade, which is well understood by those skilled inthe art and, therefore, is not shown herein.

So as to avoid non-heat conductive air gaps, the remaining interiorportion of the heat conductive watertight pipe 5, located below theground surface 4, is filled with a heat conductive fluid mixture ofwater and anti-freeze 21. For a similar purpose, the space below theground surface 4, between the exterior wall of the pipe 5 and theinterior wall of the deep well borehole 7, is filled with a heatconductive grout 22, which is in direct thermal contact with theadjacent and surrounding earth 23.

An optional low pressure cut-off switch 19 is also shown for a secondarymeans of compressor 1 shut-off in the event of a refrigerant leak orother low pressure operational event. If used, the low pressure cut-offswitch 19 should be set/designed not to shut off the compressor 1 unlessthere has been a continuous minimum of 10 minutes of system operationunder pressure conditions below the requisite minimum. However, eventhough shown herein, it is preferably unnecessary to employ the use of asecondary low pressure cut off switch 19, since the compressor's owninternal safety cut-off mechanism will shut the compressor off should itbecome overheated due to an inordinate period of operation under too lowof a refrigerant pressure condition. Thus, in a preferable design, thelow pressure cut of switch 19 shown here would simply be eliminated.

In lightening prone areas, such as the State of Florida, a designimprovement to help prevent attracting lightening to underground coppertubing would consist of placing a non-electrical conductive covering 39,such as a rubber mat or the like, over the top of the well/borehole

The operation of a low pressure cut-off switch 19, a compressor 1, anelectric powered fan 15, a self-adjusting thermal expansion valve 16,and their requisite and appropriate electrical wiring, as well as theoperation of all other system components, are well understood by thoseskilled in the art and are, therefore, neither shown nor describedherein in detail.

FIG. 22 is a side view of the sub-surface heat exchange tubing 95 withinat least one of the concrete 100, or the like, floor and walls of aswimming pool (not shown herein). The tubing 95 within the concrete 100would typically have U bends 9, which U bends 9 should preferably besurrounded with a closed cell insulation 3. The insulation 3 wouldprevent the concrete from restricting the copper tubing fromexpanding/contracting at the U bends 9, where the most stress wouldtypically occur, as the tubing 95 within the insulation 3 would be freeto expand/contract as necessary due to fluctuating temperatures, therebypreventing undue wear and tear on the tubing 95.

FIG. 23 is a side view of at least one of the floor and the wall 101 ofa swimming pool (not shown), or the like. At least one of under thefloor and behind the wall 101 of concrete, or the like, of the pool is athin plastic sheet 102. At least one of under and behind the thinplastic sheet 102 is a section of sub-surface heat exchange tubing 95,such as used in a DX heating/cooling system. At least one of under andbehind the tubing 95 is a layer of insulation 3. The insulation 3 helpsinsure the bulk of the heating/cooling effect of the DX system,transmitted to the water in the pool (not shown) through the tubing 95,is not lost into the surrounding ground. The plastic sheet 102, betweenthe tubing 95 and the concrete 100, prevents any restriction imposedupon the potential expansion/contraction of the tubing 95 under varyingtemperature conditions, as well as prevents any exposure of the tubing95 to any potentially corrosive elements by means of the concrete, orthe like, shell of the pool.

FIG. 24 is a side view of an integrity testing method for the largerO.D. vapor refrigerant transport tubing 11, and for the coupled 10smaller liquid refrigerant transport tubing 2 with a vertically orientedDX sub-surface heat exchange system, particularly where the tubing, 2and 11, is installed within a borehole/well 7 application.

Here, a small ball 103, such as a small plastic ball 103, is droppedinto the top portion 81 of the vapor line 11, and is allowed to fall, bymeans of gravity, to the bottom of the tubing, 2 and 11 near the bottom8 of the well 7. Next, a container of a pressurized gas 104, such as drynitrogen or the like, is connected by means of a pressure hose 105 tothe top portion 81 of the vapor line 11 and about fifty pounds ofpressure, or the like, is supplied into the top portion 81 of the vaporline 11. The pressure of the gas will force the small ball 103 upthrough the smaller liquid line/tube 2, and eventually into the net 106at the liquid line outlet 107. Typically, the ball 103 will exit a threehundred foot deep well within about twelve seconds if there are norestrictions in the tubing, 2 and 11. If any of the tubing, 2 and 11, isunduly restricted, the ball 103 will not be able to exit during theintegrity test. Preferably, the test will be conducted before the wellis grouted (not shown herein as grouting is well understood by thoseskilled in the art), so that if there is a problem, the tubing, 2 and11, can be withdrawn from the well 7 and repaired prior to grouting.This simple test can save thousands of dollars and time, otherwise lostif a refrigerant transport line, 2 and 11, is only found to berestricted by means of the traditional DX system operational test, afterfull job completion. A defective/restricted line set, 2 and 11, afterfull job completion, can only be corrected by means of installing acomplete new replacement line set, 2 and 11, within a newly drilled andgrouted well.

1. A direct expansion/direct exchange geothermal heating/cooling systemcomprising: a plurality of well units, each well unit including aplurality of refrigerant transportation lines; a compressor unit forprocessing refrigerant and operatively connected to the well units; adistributor operatively connected to the compressor; an energydistribution field operative connected to the compressor; a plurality ofhousing units, each housing unit positioned at a ground accessiblelocation near the compressor unit and on the distribution field side ofthe distributor, each housing unit including a pin restrictor positionedin one of the refrigerant transportation lines; a plurality of cut-offball valves, each cut-off ball valve located within one of the liquidrefrigerant transport lines and positioned beside one of the housingunits; a plurality of filters/dryers, each filter/dryer positioned inone of the refrigerant transportation lines proximate to one of the pinrestrictors; and a plurality of refrigerant flow shut-off valves, eachshut-off valves being positioned in one of the refrigeranttransportation lines containing the filter/dryer and the distributor. 2.The system of claim 1 wherein the distributor is place in either ahorizontal or vertical inclinations.